1
|
Löscher W, Gramer M, Römermann K. Heterogeneous brain distribution of bumetanide following systemic administration in rats. Biopharm Drug Dispos 2024; 45:138-148. [PMID: 38823029 DOI: 10.1002/bdd.2390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/19/2024] [Accepted: 05/16/2024] [Indexed: 06/03/2024]
Abstract
Bumetanide is used widely as a tool and off-label treatment to inhibit the Na-K-2Cl cotransporter NKCC1 in the brain and thereby to normalize intra-neuronal chloride levels in several brain disorders. However, following systemic administration, bumetanide only poorly penetrates into the brain parenchyma and does not reach levels sufficient to inhibit NKCC1. The low brain penetration is a consequence of both the high ionization rate and plasma protein binding, which restrict brain entry by passive diffusion, and of brain efflux transport. In previous studies, bumetanide was determined in the whole brain or a few brain regions, such as the hippocampus. However, the blood-brain barrier and its efflux transporters are heterogeneous across brain regions, so it cannot be excluded that bumetanide reaches sufficiently high brain levels for NKCC1 inhibition in some discrete brain areas. Here, bumetanide was determined in 14 brain regions following i.v. administration of 10 mg/kg in rats. Because bumetanide is much more rapidly eliminated by rats than humans, its metabolism was reduced by pretreatment with piperonyl butoxide. Significant, up to 5-fold differences in regional bumetanide levels were determined with the highest levels in the midbrain and olfactory bulb and the lowest levels in the striatum and amygdala. Brain:plasma ratios ranged between 0.004 (amygdala) and 0.022 (olfactory bulb). Regional brain levels were significantly correlated with local cerebral blood flow. However, regional bumetanide levels were far below the IC50 (2.4 μM) determined previously for rat NKCC1. Thus, these data further substantiate that the reported effects of bumetanide in rodent models of brain disorders are not related to NKCC1 inhibition in the brain.
Collapse
Affiliation(s)
- Wolfgang Löscher
- Translational Neuropharmacology Laboratory, NIFE, Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hannover, Germany
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Martina Gramer
- 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
| |
Collapse
|
2
|
Qin Y, Huang W, Wang Z, Wang C, Wang C, Zhang M, Wu S, Wang G, Zhao F. 1,2-Dichloroethane causes anxiety and cognitive dysfunction in mice by disturbing GABA metabolism and inhibiting the cAMP-PKA-CREB signaling pathway. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 279:116464. [PMID: 38759534 DOI: 10.1016/j.ecoenv.2024.116464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 04/09/2024] [Accepted: 05/12/2024] [Indexed: 05/19/2024]
Abstract
1,2-Dichloroethane (1,2-DCE) is a powerfully toxic neurotoxin, which is a common environmental pollutant. Studies have indicated that 1,2-DCE long-term exposure can result in adverse effects. Nevertheless, the precise mechanism remains unknown. In this study, behavioral results revealed that 1,2-DCE long-term exposure could cause anxiety and learning and memory ability impairment in mice. The contents of γ-aminobutyric acid (GABA) and glutamine (Gln) in mice's prefrontal cortex decreased, whereas that of glutamate (Glu) increased. With the increase in dose, the activities of glutamate decarboxylase (GAD) decreased and those of GABA transaminase (GABA-T) increased. The protein and mRNA expressions of GABA transporter-3 (GAT-3), vesicular GABA transporter (VGAT), GABA A receptor α2 (GABAARα2), GABAARγ2, K-Cl cotransporter isoform 2 (KCC2), GABA B receptor 1 (GABABR1), GABABR2, protein kinase A (PKA), cAMP-response element binding protein (CREB), p-CREB, brain-derived neurotrophic factor (BDNF), c-fos, c-Jun and the protein of glutamate dehydrogenase (GDH) and PKA-C were decreased, while the expression levels of GABA transporter-1 (GAT-1) and Na-K-2Cl cotransporter isoform 1 (NKCC1) were increased. However, there was no significant change in the protein content of succinic semialdehyde dehydrogenase (SSADH). The expressions of adenylate cyclase (AC) and cyclic adenosine monophosphate (cAMP) contents were also reduced. In conclusion, the results of this study show that exposure to 1,2-DCE could lead to anxiety and cognitive impairment in mice, which may be related to the disturbance of GABA metabolism and its receptors along with the cAMP-PKA-CREB pathway.
Collapse
Affiliation(s)
- Yuchen Qin
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Weiyu Huang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Zijiang Wang
- Liaoning Provincial Center for Disease Control and Prevention, Shenyang, Liaoning, People's Republic of China
| | - Chunting Wang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Chen Wang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Meng Zhang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Shengting Wu
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Gaoyang Wang
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Fenghong Zhao
- Key Laboratory of Environmental Stress and Chronic Disease Control & Prevention (China Medical University), Ministry of Education, Shenyang, Liaoning, People's Republic of China; Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, People's Republic of China.
| |
Collapse
|
3
|
Tateiwa H, Evers AS. Neurosteroids and their potential as a safer class of general anesthetics. J Anesth 2024; 38:261-274. [PMID: 38252143 PMCID: PMC10954990 DOI: 10.1007/s00540-023-03291-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 11/25/2023] [Indexed: 01/23/2024]
Abstract
Neurosteroids (NS) are a class of steroids that are synthesized within the central nervous system (CNS). Various NS can either enhance or inhibit CNS excitability and they play important biological roles in brain development, brain function and as mediators of mood. One class of NS, 3α-hydroxy-pregnane steroids such as allopregnanolone (AlloP) or pregnanolone (Preg), inhibits neuronal excitability; these endogenous NS and their analogues have been therapeutically applied as anti-depressants, anti-epileptics and general anesthetics. While NS have many favorable properties as anesthetics (e.g. rapid onset, rapid recovery, minimal cardiorespiratory depression, neuroprotection), they are not currently in clinical use, largely due to problems with formulation. Recent advances in understanding NS mechanisms of action and improved formulations have rekindled interest in development of NS as sedatives and anesthetics. In this review, the synthesis of NS, and their mechanism of action will be reviewed with specific emphasis on their binding sites and actions on γ-aminobutyric acid type A (GABAA) receptors. The potential advantages of NS analogues as sedative and anesthetic agents will be discussed.
Collapse
Affiliation(s)
- Hiroki Tateiwa
- Department of Anesthesiology and Intensive Care Medicine, Kochi Medical School, Kochi, Japan
| | - Alex S Evers
- Department of Anesthesiology, Washington University School of Medicine, 660 S Euclid Ave, St. Louis, MO, 63110, USA.
| |
Collapse
|
4
|
Zhang M, Yang L, Li Z, Fei F, Zhou Y, Jiang D, Zheng Y, Cheng H, Wang Y, Xu C, Fang J, Wang S, Chen Z, Wang Y. Low-frequency stimulation in the zona incerta attenuates seizure via driving GABAergic neuronal activity. Neurobiol Dis 2024; 192:106424. [PMID: 38290566 DOI: 10.1016/j.nbd.2024.106424] [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: 11/19/2023] [Revised: 01/15/2024] [Accepted: 01/26/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND Managing refractory epilepsy presents a significant a substantial clinical challenge. Deep brain stimulation (DBS) has emerged as a promising avenue for addressing refractory epilepsy. However, the optimal stimulation targets and effective parameters of DBS to reduce seizures remian unidentified. OBJECTIVES This study endeavors to scrutinize the therapeutic potential of DBS within the zona incerta (ZI) across diverse seizure models and elucidate the associated underlying mechanisms. METHODS We evaluated the therapeutic potential of DBS with different frequencies in the ZI on kainic acid (KA)-induced TLE model or M1-cortical seizures model, pilocarpine-induced M1-cortical seizure models, and KA-induced epilepsy model. Further, employing calcium fiber photometry combined with cell-specific ablation, we sought to clarified the causal role of ZI GABAergic neurons in mediating the therapeutic effects of DBS. RESULTS Our findings reveal that DBS in the ZI alleviated the severity of seizure activities in the KA-induced TLE model. Meanwhile, DBS attenuated seizure activities in KA- or pilocarpine-induced M1-cortical seizure model. In addition, DBS exerts a mitigating influence on KA induced epilepsy model. DBS in the ZI showed anti-seizure effects at low frequency spectrum, with 5 Hz exhibiting optimal efficacy. The low-frequency DBS significantly increased the calcium activities of ZI GABAergic neurons. Furthermore, selective ablation of ZI GABAergic neurons with taCasp3 blocked the anti-seizure effect of low-frequency DBS, indicating the anti-seizure effect of DBS is mediated by the activation of ZI GABAergic neurons. CONCLUSION Our results demonstrate that low-frequency DBS in the ZI attenuates seizure via driving GABAergic neuronal activity. This suggests that the ZI represents a potential DBS target for treating both hippocampal and cortical seizure through the activation of GABAergic neurons, thereby holding therapeutic significance for seizure treatment.
Collapse
Affiliation(s)
- Mengdi Zhang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; Zhejiang Rehabilitation Medical Center, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Lin Yang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, PR China
| | - Zhongxia Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Fan Fei
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Yuan Zhou
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Dongxiao Jiang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Yuyi Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Hui Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Yu Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China
| | - Jiajia Fang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Shuang Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China.
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, PR China; Zhejiang Rehabilitation Medical Center, The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, PR China; Epilepsy Center, Department of Neurology, Second Affiliated Hospital & Forth Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
5
|
Zhang M, Chen Y, Xu T, Jiang J, Zhang D, Huang H, Kurth CD, Yuan I, Wang R, Liu J, Zhu T, Zhou C. γ-Aminobutyric Acid-Ergic Development Contributes to the Enhancement of Electroencephalogram Slow-Delta Oscillations Under Volatile Anesthesia in Neonatal Rats. Anesth Analg 2024; 138:198-209. [PMID: 36753442 DOI: 10.1213/ane.0000000000006396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
BACKGROUND General anesthetics (eg, propofol and volatile anesthetics) enhance the slow-delta oscillations of the cortical electroencephalogram (EEG), which partly results from the enhancement of (γ-aminobutyric acid [GABA]) γ-aminobutyric acid-ergic (GABAergic) transmission. There is a GABAergic excitatory-inhibitory shift during postnatal development. Whether general anesthetics can enhance slow-delta oscillations in the immature brain has not yet been unequivocally determined. METHODS Perforated patch-clamp recording was used to confirm the reversal potential of GABAergic currents throughout GABAergic development in acute brain slices of neonatal rats. The power density of the electrocorticogram and the minimum alveolar concentrations (MAC) of isoflurane and/or sevoflurane were measured in P4-P21 rats. Then, the effects of bumetanide, an inhibitor of the Na + -K + -2Cl - cotransporter (NKCC1) and K + -Cl - cotransporter (KCC2) knockdown on the potency of volatile anesthetics and the power density of the EEG were determined in vivo. RESULTS Reversal potential of GABAergic currents were gradually hyperpolarized from P4 to P21 in cortical pyramidal neurons. Bumetanide enhanced the hypnotic effects of volatile anesthetics at P5 (for MAC LORR , isoflurane: 0.63% ± 0.07% vs 0.81% ± 0.05%, 95% confidence interval [CI], -0.257 to -0.103, P < .001; sevoflurane: 1.46% ± 0.12% vs 1.66% ± 0.09%, 95% CI, -0.319 to -0.081, P < .001); while knockdown of KCC2 weakened their hypnotic effects at P21 in rats (for MAC LORR , isoflurane: 0.58% ± 0.05% to 0.77% ± 0.20%, 95% CI, 0.013-0.357, P = .003; sevoflurane: 1.17% ± 0.04% to 1.33% ± 0.04%, 95% CI, 0.078-0.244, P < .001). For cortical EEG, slow-delta oscillations were the predominant components of the EEG spectrum in neonatal rats. Isoflurane and/or sevoflurane suppressed the power density of slow-delta oscillations rather than enhancement of it until GABAergic maturity. Enhancement of slow-delta oscillations under volatile anesthetics was simulated by preinjection of bumetanide at P5 (isoflurane: slow-delta changed ratio from -0.31 ± 0.22 to 1.57 ± 1.15, 95% CI, 0.67-3.08, P = .007; sevoflurane: slow-delta changed ratio from -0.46 ± 0.25 to 0.95 ± 0.97, 95% CI, 0.38-2.45, P = .014); and suppressed by KCC2-siRNA at P21 (isoflurane: slow-delta changed ratio from 16.13 ± 5.69 to 3.98 ± 2.35, 95% CI, -18.50 to -5.80, P = .002; sevoflurane: slow-delta changed ratio from 0.13 ± 2.82 to 3.23 ± 2.49, 95% CI, 3.02-10.79, P = .003). CONCLUSIONS Enhancement of cortical EEG slow-delta oscillations by volatile anesthetics may require mature GABAergic inhibitory transmission during neonatal development.
Collapse
Affiliation(s)
- Mingyue Zhang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Yali Chen
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Ting Xu
- Department of Anesthesiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Jingyao Jiang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Donghang Zhang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Han Huang
- Department of Anesthesiology, West China Second Hospital of Sichuan University, Chengdu, China
| | - Charles D Kurth
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Ian Yuan
- Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Rurong Wang
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Jin Liu
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Tao Zhu
- From the Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, China
| |
Collapse
|
6
|
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.
Collapse
Affiliation(s)
| | | | | | - Hai Sun
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
| |
Collapse
|
7
|
Rao S, Farhat A, Rakshasbhuvankar A, Athikarisamy S, Ghosh S, Nagarajan L. Effects of bumetanide on neonatal seizures: A systematic review of animal and human studies. Seizure 2023; 111:206-214. [PMID: 37690372 DOI: 10.1016/j.seizure.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/12/2023] Open
Abstract
BACKGROUND Bumetanide, an inhibitor of the sodium-potassium-chloride cotransporter-1, has been suggested as an adjunct to phenobarbital for treating neonatal seizures. METHODS A systematic review of animal and human studies was conducted to evaluate the efficacy and safety of bumetanide for neonatal seizures. PubMed, Embase, CINAHL and Cochrane databases were searched in March 2023. RESULTS 26 animal (rat or mice) studies describing 38 experiments (28 in-vivo and ten in-vitro) and two human studies (one RCT and one open-label dose-finding) were included. The study designs, methods to induce seizures, bumetanide dose, and outcome measures were heterogeneous, with only 4/38 experiments being in animal hypoxia/ischaemia models. Among 38 animal experiments, bumetanide was reported to have antiseizure effects in 21, pro-seizure in six and ineffective in 11. The two human studies (n = 57) did not show the benefits of bumetanide as an add-on agent to phenobarbital in their primary analyses, but one study reported benefit on post-hoc analysis. Overall, hearing impairment was detected in 5/37 surviving infants in the bumetanide group vs. 0/13 in controls. Four of the five infants with hearing impairment had received aminoglycosides concurrently. Other adverse effects reported were diuresis, mild-to-moderate dehydration, hypotension, and electrolyte disturbances. The studies did not report on long-term neurodevelopment. The certainty of the evidence was very low. CONCLUSION Animal data suggest that bumetanide has inconsistent effects as an antiseizure medication in neonates. Data from human studies are scarce and raise some concerns regarding ototoxicity when given with aminoglycosides. Well conducted studies in animal models of hypoxic-ischaemic encephalopathy are urgently needed. Future RCTs, if conducted in human neonates, should have an adequate sample size, assess neurodevelopment, minimize using aminoglycosides, be transparent about the potential ototoxicity in the parent information sheet, conduct early hearing tests and have trial-stopping rules that include hearing impairment as an outcome.
Collapse
Affiliation(s)
- Shripada Rao
- Neonatal Intensive Care Unit, King Edward Memorial and Perth Children's Hospitals, Perth, Australia; Paediatric Division, Medical School, University of Western Australia, Perth, Australia.
| | - Asifa Farhat
- General Paediatrics, Perth Children's Hospital, Perth, Australia
| | - Abhijeet Rakshasbhuvankar
- Neonatal Intensive Care Unit, King Edward Memorial and Perth Children's Hospitals, Perth, Australia; Paediatric Division, Medical School, University of Western Australia, Perth, Australia
| | - Sam Athikarisamy
- Neonatal Intensive Care Unit, King Edward Memorial and Perth Children's Hospitals, Perth, Australia; Paediatric Division, Medical School, University of Western Australia, Perth, Australia
| | - Soumya Ghosh
- Children's Neuroscience Service, Department of Neurology, Perth Children's Hospital, Perth, Australia; Centre for Neuromuscular and Neurological Disorders, Perron Institute, University of Western Australia, Perth, Australia
| | - Lakshmi Nagarajan
- Paediatric Division, Medical School, University of Western Australia, Perth, Australia; Children's Neuroscience Service, Department of Neurology, Perth Children's Hospital, Perth, Australia
| |
Collapse
|
8
|
Yan L, Yun-Lin L, Yong-Ling L, Wei-Wei Z, Yue-Shan P. Alteration of GABAergic neurons and abnormality of NKCC1/KCC2 in focal cortical dysplasia (FCD) type Ⅱ lesions. Epilepsy Res 2023; 194:107180. [PMID: 37352729 DOI: 10.1016/j.eplepsyres.2023.107180] [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: 11/11/2022] [Revised: 05/09/2023] [Accepted: 06/13/2023] [Indexed: 06/25/2023]
Abstract
BACKGROUND The current conclusions of molecular genetics still cannot satisfactorily explain the pathogenesis of focal cortical dysplasia (FCD) and the reason for drug resistance. The interneurons of GABA deserve attention. To observe the distribution and changes of GABAergic neurons and to explore the expression of cation chloride cotransporter NKCC1/KCC2 in focal cortical dysplasia (FCD) type II lesions is a highly significant job. METHODS The expressions of GAD67(a marker of active GABAergic neuron), NKCC1 and KCC2 were detected by immunohistochemistry and immunohistochemistry double staining in 10 cases of FCD Ⅱa and 10 cases of FCD Ⅱb. The number of GAD67 positive neurons was counted, and the average absorbance (IA) of NKCC1 positive expression was measured, using Image Pro-Plus7.0 software. The data were statistically analyzed. RESULTS The density of GABAergic neuron in focal dysplastic regions was significantly lower than that in the histologically "normal" cerebral cortex, regions from the same specimen (p < 0.0001, t-test). Compared to the NKCC1 staining intensity of neurons in the control group (measuring 1000 cells each), the IA value of dysmorphic neurons was significantly increased (p < 0.05, t'-test Cochran & Cox method). Intracytoplasmic concentration of KCC2 was evident in dysmorphic neurons but not in the other mature neurons. Most of the balloon cells were negative for NKCC1, except for few balloon cells showing sparse colored particles. The expression of KCC2 was negative in all balloon cells. CONCLUSIONS The changes in the expression of NKCC1 and KCC2 may indicate that dysmorphic neurons were in a state similar to that of immature neurons. This state may be related to the abnormal electrophysiology of epilepsy. The difference between the number of GAD67 positive cells in the lesion site and the remote site of the same case may be an evaluation index of the effectiveness of surgery.
Collapse
Affiliation(s)
- Li Yan
- Department of Pathology, Haidian Hospital, Haidian District of Peking University Third Hospital, Beijing, China
| | - Li Yun-Lin
- Department of Neurosurgery, Children's Hospital, Capital Institute of Pediatrics, Beijing, China
| | - Liu Yong-Ling
- Department of Pathology, Haidian Hospital, Haidian District of Peking University Third Hospital, Beijing, China
| | - Zhang Wei-Wei
- Department of Pathology, Beijing Tiantan Hospital Affiliated to Capital Medical University, Beijing, China
| | - Piao Yue-Shan
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China; Clinical Research Center for Epilepsy, Capital Medical University, Beijing 100053, China; National Center for Neurological Disorders, Beijing 100053, China.
| |
Collapse
|
9
|
Chen R, Swale DR. Functional interactions between potassium-chloride cotransporter (KCC) and inward rectifier potassium (Kir) channels in the insect central nervous system. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 192:105389. [PMID: 37105628 DOI: 10.1016/j.pestbp.2023.105389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/07/2023] [Accepted: 03/07/2023] [Indexed: 06/19/2023]
Abstract
The K+/Cl- cotransporter (KCC) is the primary mechanism by which mature neurons maintain low intracellular chloride (Cl-) concentration and has been shown to be functionally coupled to the GABA-gated chloride channels (GGCC) in Drosophila central neurons. Further, pharmacological inhibition of KCC has been shown to lead to acute toxicity of mosquitoes that highlights the toxicological relevance of insect KCC. Yet, gaps in knowledge remain regarding physiological drivers of KCC function and interactions of ion flux mechanisms upstream of GGCC in insects. Considering this, we employed electrophysiological and fluorescent microscopy techniques to further characterize KCC in the insect nervous system. Fluorescent microscopy indicated insect KCC2 is expressed in rdl neurons, which is the neuron type responsible for GABA-mediated neurotransmission, and are coexpressed with inward rectifier potassium (Kir) 2 channels. Coexpression of Kir2 and KCC2 suggested the possibility of functional coupling between these two K+ flux pathways. Indeed, extracellular recordings of Drosophila CNS showed pre-block of Kir channels prior to block of KCC led to a significant (P < 0.001) increase in CNS firing rates over baseline that when taken together, supports functional coupling of Kir to KCC function. Additionally, we documented a synergistic increase to toxicity of VU0463271, an established KCC inhibitor, above the expected additive toxicity after co-treatment with the Kir inhibitor, VU041. These data expand current knowledge regarding the physiological roles of KCC and Kir channels in the insect nervous system by defining additional pathways that facilitate inhibitory neurotransmission through GGCC.
Collapse
Affiliation(s)
- Rui Chen
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, United States of America
| | - Daniel R Swale
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, United States of America; Emerging Pathogens Institute, Department of Entomology and Nematology, University of Florida, Gainesville, FL 32610, United States of America.
| |
Collapse
|
10
|
Fogarty MJ. Inhibitory Synaptic Influences on Developmental Motor Disorders. Int J Mol Sci 2023; 24:ijms24086962. [PMID: 37108127 PMCID: PMC10138861 DOI: 10.3390/ijms24086962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
During development, GABA and glycine play major trophic and synaptic roles in the establishment of the neuromotor system. In this review, we summarise the formation, function and maturation of GABAergic and glycinergic synapses within neuromotor circuits during development. We take special care to discuss the differences in limb and respiratory neuromotor control. We then investigate the influences that GABAergic and glycinergic neurotransmission has on two major developmental neuromotor disorders: Rett syndrome and spastic cerebral palsy. We present these two syndromes in order to contrast the approaches to disease mechanism and therapy. While both conditions have motor dysfunctions at their core, one condition Rett syndrome, despite having myriad symptoms, has scientists focused on the breathing abnormalities and their alleviation-to great clinical advances. By contrast, cerebral palsy remains a scientific quagmire or poor definitions, no widely adopted model and a lack of therapeutic focus. We conclude that the sheer abundance of diversity of inhibitory neurotransmitter targets should provide hope for intractable conditions, particularly those that exhibit broad spectra of dysfunction-such as spastic cerebral palsy and Rett syndrome.
Collapse
Affiliation(s)
- Matthew J Fogarty
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN 55902, USA
| |
Collapse
|
11
|
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.
Collapse
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.
| |
Collapse
|
12
|
Cation-Chloride Cotransporters KCC2 and NKCC1 as Therapeutic Targets in Neurological and Neuropsychiatric Disorders. Molecules 2023; 28:molecules28031344. [PMID: 36771011 PMCID: PMC9920462 DOI: 10.3390/molecules28031344] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/21/2023] [Accepted: 01/25/2023] [Indexed: 02/04/2023] Open
Abstract
Neurological diseases including Alzheimer's, Huntington's disease, Parkinson's disease, Down syndrome and epilepsy, and neuropsychiatric disorders such as schizophrenia, are conditions that affect not only individuals but societies on a global scale. Current therapies offer a means for small symptomatic relief, but recently there has been increasing demand for therapeutic alternatives. The γ-aminobutyric acid (GABA)ergic signaling system has been investigated for developing new therapies as it has been noted that any dysfunction or changes to this system can contribute to disease progression. Expression of the K-Cl-2 (KCC2) and N-K-C1-1 (NKCC1) cation-chloride cotransporters (CCCs) has recently been linked to the disruption of GABAergic activity by affecting the polarity of GABAA receptor signaling. KCC2 and NKCC1 play a part in multiple neurological and neuropsychiatric disorders, making them a target of interest for potential therapies. This review explores current research suggesting the pathophysiological role and therapeutic importance of KCC2 and NKCC1 in neuropsychiatric and neurological disorders.
Collapse
|
13
|
Talifu Z, Pan Y, Gong H, Xu X, Zhang C, Yang D, Gao F, Yu Y, Du L, Li J. The role of KCC2 and NKCC1 in spinal cord injury: From physiology to pathology. Front Physiol 2022; 13:1045520. [PMID: 36589461 PMCID: PMC9799334 DOI: 10.3389/fphys.2022.1045520] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
The balance of ion concentrations inside and outside the cell is an essential homeostatic mechanism in neurons and serves as the basis for a variety of physiological activities. In the central nervous system, NKCC1 and KCC2, members of the SLC12 cation-chloride co-transporter (CCC) family, participate in physiological and pathophysiological processes by regulating intracellular and extracellular chloride ion concentrations, which can further regulate the GABAergic system. Over recent years, studies have shown that NKCC1 and KCC2 are essential for the maintenance of Cl- homeostasis in neural cells. NKCC1 transports Cl- into cells while KCC2 transports Cl- out of cells, thereby regulating chloride balance and neuronal excitability. An imbalance of NKCC1 and KCC2 after spinal cord injury will disrupt CI- homeostasis, resulting in the transformation of GABA neurons from an inhibitory state into an excitatory state, which subsequently alters the spinal cord neural network and leads to conditions such as spasticity and neuropathic pain, among others. Meanwhile, studies have shown that KCC2 is also an essential target for motor function reconstruction after spinal cord injury. This review mainly introduces the physiological structure and function of NKCC1 and KCC2 and discusses their pathophysiological roles after spinal cord injury.
Collapse
Affiliation(s)
- Zuliyaer Talifu
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Yunzhu Pan
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Han Gong
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Xin Xu
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Chunjia Zhang
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Degang Yang
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Feng Gao
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Yan Yu
- School of Rehabilitation, Capital Medical University, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Liangjie Du
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,*Correspondence: Liangjie Du, ; Jianjun Li,
| | - Jianjun Li
- School of Rehabilitation, Capital Medical University, Beijing, China,Department of Spinal and Neural Functional Reconstruction, China Rehabilitation Research Center, Beijing, China,Chinese Institute of Rehabilitation Science, Beijing, China,Center of Neural Injury and Repair, Beijing Institute for Brain Disorders, Beijing, China,Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China,School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao, China,*Correspondence: Liangjie Du, ; Jianjun Li,
| |
Collapse
|
14
|
Janoš P, Magistrato A. Role of Monovalent Ions in the NKCC1 Inhibition Mechanism Revealed through Molecular Simulations. Int J Mol Sci 2022; 23:ijms232315439. [PMID: 36499764 PMCID: PMC9741434 DOI: 10.3390/ijms232315439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
The secondary active Na-K-Cl cotransporter 1 (NKCC1) promotes electroneutral uptake of two chloride ions, one sodium ion and one potassium ion. NKCC1 regulates Cl- homeostasis, thus being implicated in transepithelial water transport and in neuronal excitability. Aberrant NKCC1 transport is linked to a variety of human diseases. The loop diuretic drugs bumetanide, furosemide, azosemide and ethacrynic acid target NKCC1, but are characterized by poor selectivity leading to severe side effects. Despite its therapeutic importance, the molecular details of the NKCC1 inhibition mechanism remain unclear. Using all-atom simulations, we predict a putative binding mode of these drugs to the zebrafish (z) and human (h) NKCC1 orthologs. Although differing in their specific interactions with NKCC1 and/or monovalent ions, all drugs can fit within the same cavity and engage in hydrophobic interactions with M304/M382 in z/hNKCC1, a proposed ion gating residue demonstrated to be key for bumetanide binding. Consistent with experimental evidence, all drugs take advantage of the K+/Na+ ions, which plastically respond to their binding. This study not only provides atomic-level insights useful for drug discovery campaigns of more selective/potent NKCC1 inhibitors aimed to tackle diseases related to deregulated Cl- homeostasis, but it also supplies a paradigmatic example of the key importance of dynamical effects when drug binding is mediated by monovalent ions.
Collapse
|
15
|
Gan Y, Wei Z, Liu C, Li G, Feng Y, Deng Y. Solute carrier transporter disease and developmental and epileptic encephalopathy. Front Neurol 2022; 13:1013903. [PMID: 36419532 PMCID: PMC9676364 DOI: 10.3389/fneur.2022.1013903] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/07/2022] [Indexed: 09/14/2023] Open
Abstract
The International League Against Epilepsy officially revised its classification in 2017, which amended "epileptic encephalopathy" to "developmental and epileptic encephalopathy". With the development of genetic testing technology, an increasing number of genes that cause developmental and epileptic encephalopathies are being identified. Among these, solute transporter dysfunction is part of the etiology of developmental and epileptic encephalopathies. Solute carrier transporters play an essential physiological function in the human body, and their dysfunction is associated with various human diseases. Therefore, in-depth studies of developmental and epileptic encephalopathies caused by solute carrier transporter dysfunction can help develop new therapeutic modalities to facilitate the treatment of refractory epilepsy and improve patient prognosis. In this article, the concept of transporter protein disorders is first proposed, and nine developmental and epileptic encephalopathies caused by solute carrier transporter dysfunction are described in detail in terms of pathogenesis, clinical manifestations, ancillary tests, and precise treatment to provide ideas for the precise treatment of epilepsy.
Collapse
Affiliation(s)
- Yajing Gan
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Zihan Wei
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Chao Liu
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Guoyan Li
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yan Feng
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yanchun Deng
- Department of Neurology, Epilepsy Center of Xijing Hospital, Fourth Military Medical University, Xi'an, China
- Xijing Institute of Epilepsy and Encephalopathy, Xi'an, China
| |
Collapse
|
16
|
Miles KD, Doll CA. Chloride imbalance in Fragile X syndrome. Front Neurosci 2022; 16:1008393. [PMID: 36312023 PMCID: PMC9596984 DOI: 10.3389/fnins.2022.1008393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/20/2022] [Indexed: 11/26/2022] Open
Abstract
Developmental changes in ionic balance are associated with crucial hallmarks in neural circuit formation, including changes in excitation and inhibition, neurogenesis, and synaptogenesis. Neuronal excitability is largely mediated by ionic concentrations inside and outside of the cell, and chloride (Cl-) ions are highly influential in early neurodevelopmental events. For example, γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter of the mature central nervous system (CNS). However, during early development GABA can depolarize target neurons, and GABAergic depolarization is implicated in crucial neurodevelopmental processes. This developmental shift of GABAergic neurotransmission from depolarizing to hyperpolarizing output is induced by changes in Cl- gradients, which are generated by the relative expression of Cl- transporters Nkcc1 and Kcc2. Interestingly, the GABA polarity shift is delayed in Fragile X syndrome (FXS) models; FXS is one of the most common heritable neurodevelopmental disorders. The RNA binding protein FMRP, encoded by the gene Fragile X Messenger Ribonucleoprotein-1 (Fmr1) and absent in FXS, appears to regulate chloride transporter expression. This could dramatically influence FXS phenotypes, as the syndrome is hypothesized to be rooted in defects in neural circuit development and imbalanced excitatory/inhibitory (E/I) neurotransmission. In this perspective, we summarize canonical Cl- transporter expression and investigate altered gene and protein expression of Nkcc1 and Kcc2 in FXS models. We then discuss interactions between Cl- transporters and neurotransmission complexes, and how these links could cause imbalances in inhibitory neurotransmission that may alter mature circuits. Finally, we highlight current therapeutic strategies and promising new directions in targeting Cl- transporter expression in FXS patients.
Collapse
Affiliation(s)
| | - Caleb Andrew Doll
- Department of Pediatrics, Section of Developmental Biology, University of Colorado School of Medicine, Children’s Hospital Colorado, Aurora, CO, United States
| |
Collapse
|
17
|
Proskurina EY, Zaitsev AV. Regulation of Potassium and Chloride Concentrations in Nervous Tissue as a Method of Anticonvulsant Therapy. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022050015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Abstract
Under some pathological conditions, such as pharmacoresistant
epilepsy, status epilepticus or certain forms of genetic abnormalities,
spiking activity of GABAergic interneurons may enhance excitation
processes in neuronal circuits and provoke the generation of ictal
discharges. As a result, anticonvulsants acting on the GABAergic
system may be ineffective or even increase seizure activity. This
paradoxical effect of the inhibitory system is due to ionic imbalances
in nervous tissue. This review addresses the mechanisms of ictal
discharge initiation in neuronal networks due to the imbalance of
chloride and potassium ions, as well as possible ways to regulate
ionic concentrations. Both the enhancement (or attenuation) of the
activity of certain neuronal ion transporters and ion pumps and
their additional expression via gene therapy can be effective in
suppressing seizure activity caused by ionic imbalances. The Na+–K+-pump,
NKCC1 and KCC2 cotransporters are important for maintaining proper
K+ and Cl– concentrations
in nervous tissue, having been repeatedly considered as pharmacological
targets for antiepileptic exposures. Further progress in this direction
is hampered by the lack of sufficiently selective pharmacological
tools and methods for providing effective drug delivery to the epileptic
focus. The use of the gene therapy techniques, such as overexpressing
of the KCC2 transporter in the epileptic focus, seems to be a more promising
approach. Another possible direction could be the use of optogenetic
tools, namely specially designed light-activated ion pumps or ion
channels. In this case, photon energy can be used to create the
required gradients of chloride and potassium ions, although these
methods also have significant limitations which complicate their
rapid introduction into medicine.
Collapse
|
18
|
Bialer M, Johannessen SI, Koepp MJ, Levy RH, Perucca E, Perucca P, Tomson T, White HS. Progress report on new antiepileptic drugs: A summary of the Sixteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XVI): II. Drugs in more advanced clinical development. Epilepsia 2022; 63:2883-2910. [PMID: 35950617 DOI: 10.1111/epi.17376] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 11/27/2022]
Abstract
The Sixteenth Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XVI) was held in Madrid, Spain on May 22-25, 2022 and was attended by 157 delegates from 26 countries representing basic and clinical science, regulatory agencies, and pharmaceutical industries. One day of the conference was dedicated to sessions presenting and discussing investigational compounds under development for the treatment of seizures and epilepsy. The current progress report summarizes recent findings and current knowledge for seven of these compounds in more advanced clinical development for which either novel preclinical or patient data are available. These compounds include bumetanide and its derivatives, darigabat, ganaxolone, lorcaserin, soticlestat, STK-001, and XEN1101. Of these, ganaxolone was approved by the US Food and Drug Administration in March 2022 for the treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder in patients 2 years of age and older.
Collapse
Affiliation(s)
- Meir Bialer
- Institute for Drug Research, Faculty of Medicine, School of Pharmacy, and David R. Bloom Center for Pharmacy, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Svein I Johannessen
- National Center for Epilepsy, Sandvika, Norway.,Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - René H Levy
- Department of Pharmaceutics and Neurological Surgery, University of Washington, Seattle, Washington, USA
| | - Emilio Perucca
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria, Australia.,Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Piero Perucca
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria, Australia.,Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Melbourne, Victoria, Australia.,Department of Neurology, The Royal Melbourne Hospital, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| |
Collapse
|
19
|
Carnovale C, Perrotta C, Baldelli S, Cattaneo D, Montrasio C, Barbieri SS, Pompilio G, Vantaggiato C, Clementi E, Pozzi M. Antihypertensive drugs and brain function: mechanisms underlying therapeutically beneficial and harmful neuropsychiatric effects. Cardiovasc Res 2022; 119:647-667. [PMID: 35895876 PMCID: PMC10153433 DOI: 10.1093/cvr/cvac110] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 06/15/2022] [Accepted: 06/21/2022] [Indexed: 11/14/2022] Open
Abstract
A bidirectional relationship exists between hypertension and psychiatric disorders, including unipolar and bipolar depression, anxiety, post-traumatic stress disorder (PTSD), psychosis, schizophrenia, mania, and dementia/cognitive decline. Repurposing of antihypertensive drugs to treat mental disorders is thus being explored. A systematic knowledge of the mechanisms of action and clinical consequences of the use of antihypertensive agents on neuropsychiatric functions has not been achieved yet. In this article, we review the putative role of antihypertensive agents in psychiatric disorders, discuss the targets and mechanisms of action, and examine how and to what extent specific drug classes/molecules may trigger, worsen, or mitigate psychiatric symptoms. In addition, we review pharmacokinetics (brain penetration of drugs) and pharmacogenetics data that add important information to assess risks and benefits of antihypertensive drugs in neuropsychiatric settings. The scientific literature shows robust evidence of a positive effect of α1 blockers on PTSD symptoms, nightmares and sleep quality, α2 agonists on core symptoms, executive function and quality of life in Attention-Deficit/Hyperactivity Disorder, PTSD, Tourette's syndrome, and β blockers on anxiety, aggression, working memory, and social communication. Renin-angiotensin system modulators exert protective effects on cognition, depression, and anxiety, and the loop diuretic bumetanide reduced the core symptoms of autism in a subset of patients. There is no evidence of clear benefits of calcium channel blockers in mood disorders in the scientific literature. These findings are mainly from preclinical studies; clinical data are still insufficient or of anecdotal nature, and seldom systematic. The information herewith provided can support a better therapeutic approach to hypertension, tailored to patients with, or with high susceptibility to, psychiatric illness. It may prompt clinical studies exploring the potential benefit of antihypertensive drugs in selected patients with neuropsychiatric comorbidities that include outcomes of neuropsychiatric interest and specifically assess undesirable effects or interactions.
Collapse
Affiliation(s)
- Carla Carnovale
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences (DIBIC), ASST Fatebenefratelli-Sacco University Hospital, Università degli Studi di Milano, 20157 Milano, Italy
| | - Cristiana Perrotta
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences (DIBIC), ASST Fatebenefratelli-Sacco University Hospital, Università degli Studi di Milano, 20157 Milano, Italy
| | - Sara Baldelli
- Unit of Clinical Pharmacology, ASST Fatebenefratelli-Sacco University Hospital, 20157 Milano, Italy
| | - Dario Cattaneo
- Unit of Clinical Pharmacology, ASST Fatebenefratelli-Sacco University Hospital, 20157 Milano, Italy
| | - Cristina Montrasio
- Unit of Clinical Pharmacology, ASST Fatebenefratelli-Sacco University Hospital, 20157 Milano, Italy
| | - Silvia S Barbieri
- Unit of Brain-Heart axis: cellular and molecular mechanisms - Centro Cardiologico Monzino IRCCS, 20138 Milano, Italy
| | - Giulio Pompilio
- Unit of Vascular Biology and Regenerative Medicine - Centro Cardiologico Monzino IRCCS, 20138, Milan, Italy.,Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy
| | | | - Emilio Clementi
- Unit of Clinical Pharmacology, Department of Biomedical and Clinical Sciences (DIBIC), ASST Fatebenefratelli-Sacco University Hospital, Università degli Studi di Milano, 20157 Milano, Italy.,Scientific Institute IRCCS Eugenio Medea, Bosisio Parini (LC), Italy
| | - Marco Pozzi
- Scientific Institute IRCCS Eugenio Medea, Bosisio Parini (LC), Italy
| |
Collapse
|
20
|
Zhao Y, Shen J, Wang Q, Ruiz Munevar MJ, Vidossich P, De Vivo M, Zhou M, Cao E. Structure of the human cation-chloride cotransport KCC1 in an outward-open state. Proc Natl Acad Sci U S A 2022; 119:e2109083119. [PMID: 35759661 PMCID: PMC9271165 DOI: 10.1073/pnas.2109083119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 04/25/2022] [Indexed: 12/30/2022] Open
Abstract
Cation-chloride cotransporters (CCCs) catalyze electroneutral symport of Cl- with Na+ and/or K+ across membranes. CCCs are fundamental in cell volume homeostasis, transepithelia ion movement, maintenance of intracellular Cl- concentration, and neuronal excitability. Here, we present a cryoelectron microscopy structure of human K+-Cl- cotransporter (KCC)1 bound with the VU0463271 inhibitor in an outward-open state. In contrast to many other amino acid-polyamine-organocation transporter cousins, our first outward-open CCC structure reveals that opening the KCC1 extracellular ion permeation path does not involve hinge-bending motions of the transmembrane (TM) 1 and TM6 half-helices. Instead, rocking of TM3 and TM8, together with displacements of TM4, TM9, and a conserved intracellular loop 1 helix, underlie alternate opening and closing of extracellular and cytoplasmic vestibules. We show that KCC1 intriguingly exists in one of two distinct dimeric states via different intersubunit interfaces. Our studies provide a blueprint for understanding the mechanisms of CCCs and their inhibition by small molecule compounds.
Collapse
Affiliation(s)
- Yongxiang Zhao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Jiemin Shen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Qinzhe Wang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | | | | | - Marco De Vivo
- Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| |
Collapse
|
21
|
Chen L, Yu J, Wan L, Wu Z, Wang G, Hu Z, Ren L, Zhou J, Qian B, Zhao X, Zhang J, Liu X, Wang Y. Furosemide prevents membrane KCC2 downregulation during convulsant stimulation in the hippocampus. IBRO Neurosci Rep 2022; 12:355-365. [PMID: 35746976 PMCID: PMC9210493 DOI: 10.1016/j.ibneur.2022.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/15/2022] [Accepted: 04/25/2022] [Indexed: 02/08/2023] Open
Abstract
In adults, γ-aminobutyric acid (GABA) type A receptor (GABAAR)-mediated inhibition depends on the maintenance of low intracellular chloride anion concentration through neuron-specific potassium-chloride cotransporter-2 (KCC2). KCC2 has been widely reported to have a plasticity change during the course of epilepsy development, with an early downregulation and late recovery in neuronal cell membranes after epileptic stimulation, which facilitates epileptiform burst activity. Furosemide is a clinical loop diuretic that inhibits KCC2. Here, we first confirmed that furosemide pretreatment could effectively prevented convulsant stimulation-induced neuronal membrane KCC2 downregulation in the hippocampus in both in vivo and in vitro cyclothiazide-induced seizure model. Second, we verified that furosemide pretreatment rescued KCC2 function deficits, as indicated by E GABA depolarizing shift and GABAAR inhibitory function impairment induced via cyclothiazide treatment. Further, we demonstrated that furosemide also suppressed cyclothiazide-induced epileptiform burst activity in cultured hippocampal neurons and lowered the mortality rate during acute seizure induction. Overall, furosemide prevents membrane KCC2 downregulation during acute seizure induction, restores KCC2-mediated GABA inhibition, and interrupts the progression from acute seizure to epileptogenesis.
Collapse
Affiliation(s)
- Lulan Chen
- 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
| | - Jiangning Yu
- 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
| | - Li Wan
- 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
- Rehabilitation Center, Shenzhen Second People's Hospital/ the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518035, China Institute of
| | - Zheng Wu
- 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
| | - Guoxiang 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
| | - Zihan Hu
- Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Liang Ren
- 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
| | - 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
- Rehabilitation Center, Shenzhen Second People's Hospital/ the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen 518035, China Institute of
| | - Binbin Qian
- 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
| | - Xuan Zhao
- Department of Anesthesiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Correspondence to: Department of Anesthesiology, Shanghai Tenth People’s Hospital, China.
| | - Jinwei Zhang
- Biomedical and Clinical Sciences, Medical School, College of Medicine and Health, University of Exeter, Hatherly Laboratories, Exeter EX4 4PS, UK
| | - Xu Liu
- 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
- Correspondence to: Department of Neurology, Zhongshan Hospital, Fudan University, 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
- Correspondence to: Institutes of Brain Science, Fudan University, Shanghai 200032, China.
| |
Collapse
|
22
|
Juarez-Martinez EL, van Andel DM, Sprengers JJ, Avramiea AE, Oranje B, Scheepers FE, Jansen FE, Mansvelder HD, Linkenkaer-Hansen K, Bruining H. Bumetanide Effects on Resting-State EEG in Tuberous Sclerosis Complex in Relation to Clinical Outcome: An Open-Label Study. Front Neurosci 2022; 16:879451. [PMID: 35645706 PMCID: PMC9134117 DOI: 10.3389/fnins.2022.879451] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/15/2022] [Indexed: 12/05/2022] Open
Abstract
Neuronal excitation-inhibition (E/I) imbalances are considered an important pathophysiological mechanism in neurodevelopmental disorders. Preclinical studies on tuberous sclerosis complex (TSC), suggest that altered chloride homeostasis may impair GABAergic inhibition and thereby E/I-balance regulation. Correction of chloride homeostasis may thus constitute a treatment target to alleviate behavioral symptoms. Recently, we showed that bumetanide-a chloride-regulating agent-improved behavioral symptoms in the open-label study Bumetanide to Ameliorate Tuberous Sclerosis Complex Hyperexcitable Behaviors trial (BATSCH trial; Eudra-CT: 2016-002408-13). Here, we present resting-state EEG as secondary analysis of BATSCH to investigate associations between EEG measures sensitive to network-level changes in E/I balance and clinical response to bumetanide. EEGs of 10 participants with TSC (aged 8-21 years) were available. Spectral power, long-range temporal correlations (LRTC), and functional E/I ratio (fE/I) in the alpha-frequency band were compared before and after 91 days of treatment. Pre-treatment measures were compared against 29 typically developing children (TDC). EEG measures were correlated with the Aberrant Behavioral Checklist-Irritability subscale (ABC-I), the Social Responsiveness Scale-2 (SRS-2), and the Repetitive Behavior Scale-Revised (RBS-R). At baseline, TSC showed lower alpha-band absolute power and fE/I than TDC. Absolute power increased through bumetanide treatment, which showed a moderate, albeit non-significant, correlation with improvement in RBS-R. Interestingly, correlations between baseline EEG measures and clinical outcomes suggest that most responsiveness might be expected in children with network characteristics around the E/I balance point. In sum, E/I imbalances pointing toward an inhibition-dominated network are present in TSC. We established neurophysiological effects of bumetanide although with an inconclusive relationship with clinical improvement. Nonetheless, our results further indicate that baseline network characteristics might influence treatment response. These findings highlight the possible utility of E/I-sensitive EEG measures to accompany new treatment interventions for TSC. Clinical Trial Registration EU Clinical Trial Register, EudraCT 2016-002408-13 (www.clinicaltrialsregister.eu/ctr-search/trial/2016-002408-13/NL). Registered 25 July 2016.
Collapse
Affiliation(s)
- Erika L. Juarez-Martinez
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, Netherlands
- Child and Adolescent Psychiatry and Psychosocial Care, Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Dorinde M. van Andel
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Jan J. Sprengers
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Arthur-Ervin Avramiea
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, Netherlands
| | - Bob Oranje
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Floortje E. Scheepers
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Floor E. Jansen
- Department of Pediatric Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Huibert D. Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, Netherlands
| | - Klaus Linkenkaer-Hansen
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, Netherlands
| | - Hilgo Bruining
- Child and Adolescent Psychiatry and Psychosocial Care, Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Department of Psychiatry, UMC Utrecht Brain Center, University Medical Centre Utrecht, Utrecht, Netherlands
- N=You Neurodevelopmental Precision Center, Amsterdam Neuroscience, Amsterdam Reproduction and Development, Amsterdam UMC, Amsterdam, Netherlands
- Levvel, Academic Center for Child and Adolescent Psychiatry, Amsterdam, Netherlands
| |
Collapse
|
23
|
Why won't it stop? The dynamics of benzodiazepine resistance in status epilepticus. Nat Rev Neurol 2022; 18:428-441. [PMID: 35538233 DOI: 10.1038/s41582-022-00664-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 11/08/2022]
Abstract
Status epilepticus is a life-threatening neurological emergency that affects both adults and children. Approximately 36% of episodes of status epilepticus do not respond to the current preferred first-line treatment, benzodiazepines. The proportion of episodes that are refractory to benzodiazepines is higher in low-income and middle-income countries (LMICs) than in high-income countries (HICs). Evidence suggests that longer episodes of status epilepticus alter brain physiology, thereby contributing to the emergence of benzodiazepine resistance. Such changes include alterations in GABAA receptor function and in the transmembrane gradient for chloride, both of which erode the ability of benzodiazepines to enhance inhibitory synaptic signalling. Often, current management guidelines for status epilepticus do not account for these duration-related changes in pathophysiology, which might differentially impact individuals in LMICs, where the average time taken to reach medical attention is longer than in HICs. In this Perspective article, we aim to combine clinical insights and the latest evidence from basic science to inspire a new, context-specific approach to efficiently managing status epilepticus.
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Thompson K. Status epilepticus and early development: neuronal injury, neurodegeneration, and their consequences. Epilepsia Open 2022; 8 Suppl 1:S110-S116. [PMID: 35434910 PMCID: PMC10173843 DOI: 10.1002/epi4.12601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 11/07/2022] Open
Abstract
Evidence showing that the immature brain is vulnerable to seizure-induced damage has been accumulating for decades. Clinical data have always suggested that some early-life seizures are associated with negative sequelae, but clinical observations are frequently obscured by multiple uncontrolled contributing factors and can rarely establish causality. Determining with certainty that seizures, per se, can cause neuronal death and can irreversibly disrupt critical developmental processes, required the development of suitable model systems. Several experimental seizure models clearly show that the immature brain can sustain neuronal injury as a result of uncontrolled seizure activity and that even in the absence of observable neuronal death, the developing brain is selectively vulnerable to interruptions of required growth programs. Severe early-life seizures inhibit DNA, RNA, and protein synthesis, and they can reduce the accumulation of myelin and synaptic markers in the developing nervous system, leading to functional delays in development. Depending on the seizure pathway involved, and the developmental period under study, classic neurodegeneration, excitotoxicity, and apoptosis can result in permanent damage to critical neural networks in the temporal lobe and in many other brain regions. This conclusion is further supported by recent clinical studies showing that prolonged febrile status epilepticus can lead to hippocampal injury, which evolves into hippocampal atrophy and hippocampal sclerosis. A growing body of experimental data demonstrates that the metabolic compromise and cellular loss produced by seizures during critical phases of brain development negatively affect later hippocampal physiology including learning and memory functions in maturity.
Collapse
Affiliation(s)
- Kerry Thompson
- Occidental College Department of Biology, 1600 Campus Rd Los Angeles CA USA
| |
Collapse
|
26
|
Wang J, Liu W, Xu W, Yang B, Cui M, Li Z, Zhang H, Jin C, Xue H, Zhang J. Comprehensive Analysis of the Oncogenic, Genomic Alteration, and Immunological Landscape of Cation-Chloride Cotransporters in Pan-Cancer. Front Oncol 2022; 12:819688. [PMID: 35372048 PMCID: PMC8968682 DOI: 10.3389/fonc.2022.819688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Background Assessing the phenotypic diversity underlying tumor progression requires the identification of variations in the respective molecular interaction in the tumor microenvironment (TME). Despite emerging studies focusing on the association between cation-chloride cotransporters (CCCs) and carcinogenesis, direct evidence that CCCs (KCC2 and NKCC1) mediate tumor progression in pan-cancer remains unclear. Methods We conducted a comprehensive assessment of the expression, DNA variation profiles, and prognostic and immunologic implications of CCCs based on a large-scale pan-cancer population, including 10,967 cancer patients from the Cancer Genome Atlas, 9,162 cancer patients from Genomics Expression Omnibus, 48,834 cancer patients from 188 independent studies, and 356 cancer patients from three real-world cohorts. Results In this study, we first found that CCCs were highly expressed in most tumors, and prominently associated with prognosis. Kaplan–Meier analysis and Cox regression analysis revealed that KCC2 and NKCC1 significantly predicted survival for patients with pan-cancer, suggesting that CCCs have inconsistent tumorigenesis regulatory mechanisms in cancers. Next, we examined the DNA variation landscape of KCC2 and NKCC1 and their prognostic implications in pan-cancer. The results demonstrated that UCEC patients with somatic copy number variation (CNV) of NKCC1 received significantly better outcomes (p < 0.05). Besides emphasizing the clinical implications of CNV of CCCs for cancer patients, we found that NKCC1MUT could prominently prolong progression-free survival (p = 2.59e-04), disease-specific survival (p = 0.019), and overall survival (p = 0.034) compared with NKCC1WT cancer patients possibly via regulation of cell proliferation and oncogenic stress pathways. Additionally, KCC2 positively correlated with the levels of tumor-infiltrating macrophages and CD4+ T cells, but NKCC1 showed a significantly widely negative association with tumor-infiltrated lymphocytes, suggesting an immune-excluded TME in cancers. Similarly, expression of KCC2, rather than NKCC1, was positively correlated with the immune checkpoint molecules, indicating its role as an immune regulator in a wide variety of cancers. Finally, to verify our hypothesis and altered expression of CCCs, we performed IHC analysis and revealed the staining distribution in tumor and adjacent normal tissues of glioma, clear cell renal cell carcinoma, papillary cell renal cell carcinoma, and hepatocellular and breast cancer from three real-world cohorts, and validated prominently prognostic implications of CCCs in patients with clear cell renal cell carcinoma. Conclusion This study first comprehensively investigated the molecular and clinical role of CCCs, and illustrated the significant association among KCC2/NKCC1 expression, DNA variation profiles prognosis, and TME of pan-cancer. The pan-cancer findings provided an in-depth understanding of potential oncogenic and immunologic of differential expression and DNA alteration of KCC2/NKCC1 cancers.
Collapse
Affiliation(s)
- Jie Wang
- Department of Anesthesiology and Perioperative Medicine, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Wangrui Liu
- Department of Neurosurgery, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China
| | - Wenhao Xu
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Baofeng Yang
- Department of Anesthesiology and Perioperative Medicine, Affiliate Cancer Hospital of Zhengzhou University, Zhengzhou, China
| | - Mingzhu Cui
- Department of Anesthesiology and Perioperative Medicine, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Zhen Li
- Department of Pathology, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China
| | - Hailiang Zhang
- Department of Urology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Chuntao Jin
- Department of Neurosurgery, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China
- *Correspondence: Jiaqiang Zhang, ; Huanzhou Xue, ; Chuntao Jin,
| | - Huanzhou Xue
- Department of Hepatobiliary Surgery, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
- *Correspondence: Jiaqiang Zhang, ; Huanzhou Xue, ; Chuntao Jin,
| | - Jiaqiang Zhang
- Department of Anesthesiology and Perioperative Medicine, People’s Hospital of Zhengzhou University, Henan Provincial People’s Hospital, Zhengzhou, China
- *Correspondence: Jiaqiang Zhang, ; Huanzhou Xue, ; Chuntao Jin,
| |
Collapse
|
27
|
Ben-Ari Y, Cherubini E. The GABA Polarity Shift and Bumetanide Treatment: Making Sense Requires Unbiased and Undogmatic Analysis. Cells 2022; 11:396. [PMID: 35159205 PMCID: PMC8834580 DOI: 10.3390/cells11030396] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/05/2022] [Accepted: 01/13/2022] [Indexed: 12/17/2022] Open
Abstract
GABA depolarizes and often excites immature neurons in all animal species and brain structures investigated due to a developmentally regulated reduction in intracellular chloride concentration ([Cl-]i) levels. The control of [Cl-]i levels is mediated by the chloride cotransporters NKCC1 and KCC2, the former usually importing chloride and the latter exporting it. The GABA polarity shift has been extensively validated in several experimental conditions using often the NKCC1 chloride importer antagonist bumetanide. In spite of an intrinsic heterogeneity, this shift is abolished in many experimental conditions associated with developmental disorders including autism, Rett syndrome, fragile X syndrome, or maternal immune activation. Using bumetanide, an EMA- and FDA-approved agent, many clinical trials have shown promising results with the expected side effects. Kaila et al. have repeatedly challenged these experimental and clinical observations. Here, we reply to the recent reviews by Kaila et al. stressing that the GABA polarity shift is solidly accepted by the scientific community as a major discovery to understand brain development and that bumetanide has shown promising effects in clinical trials.
Collapse
Affiliation(s)
- Yehezkel Ben-Ari
- Neurochlore, Batiment Beret Delaage, Campus Scientifique de Luminy, 13009 Marseille, France
| | - Enrico Cherubini
- European Brain Research Institute (EBRI)-Rita Levi-Montalcini, 00161 Roma, Italy;
| |
Collapse
|
28
|
Tóth K, Lénárt N, Berki P, Fekete R, Szabadits E, Pósfai B, Cserép C, Alatshan A, Benkő S, Kiss D, Hübner CA, Gulyás A, Kaila K, Környei Z, Dénes Á. The NKCC1 ion transporter modulates microglial phenotype and inflammatory response to brain injury in a cell-autonomous manner. PLoS Biol 2022; 20:e3001526. [PMID: 35085235 PMCID: PMC8856735 DOI: 10.1371/journal.pbio.3001526] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/18/2022] [Accepted: 01/04/2022] [Indexed: 12/25/2022] Open
Abstract
The NKCC1 ion transporter contributes to the pathophysiology of common neurological disorders, but its function in microglia, the main inflammatory cells of the brain, has remained unclear to date. Therefore, we generated a novel transgenic mouse line in which microglial NKCC1 was deleted. We show that microglial NKCC1 shapes both baseline and reactive microglia morphology, process recruitment to the site of injury, and adaptation to changes in cellular volume in a cell-autonomous manner via regulating membrane conductance. In addition, microglial NKCC1 deficiency results in NLRP3 inflammasome priming and increased production of interleukin-1β (IL-1β), rendering microglia prone to exaggerated inflammatory responses. In line with this, central (intracortical) administration of the NKCC1 blocker, bumetanide, potentiated intracortical lipopolysaccharide (LPS)-induced cytokine levels. In contrast, systemic bumetanide application decreased inflammation in the brain. Microglial NKCC1 KO animals exposed to experimental stroke showed significantly increased brain injury, inflammation, cerebral edema and worse neurological outcome. Thus, NKCC1 emerges as an important player in controlling microglial ion homeostasis and inflammatory responses through which microglia modulate brain injury. The contribution of microglia to central NKCC1 actions is likely to be relevant for common neurological disorders.
Collapse
Affiliation(s)
- Krisztina Tóth
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Nikolett Lénárt
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Péter Berki
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Rebeka Fekete
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Eszter Szabadits
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Balázs Pósfai
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Csaba Cserép
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Ahmad Alatshan
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cellular and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Szilvia Benkő
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cellular and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dániel Kiss
- Software Engineering Institute, John von Neumann Faculty of Informatics, Óbuda University, Budapest, Hungary
| | | | - Attila Gulyás
- Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary
| | - Kai Kaila
- Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Zsuzsanna Környei
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
| | - Ádám Dénes
- Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary
- * E-mail:
| |
Collapse
|
29
|
Kilb W. When Are Depolarizing GABAergic Responses Excitatory? Front Mol Neurosci 2021; 14:747835. [PMID: 34899178 PMCID: PMC8651619 DOI: 10.3389/fnmol.2021.747835] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/28/2021] [Indexed: 11/13/2022] Open
Abstract
The membrane responses upon activation of GABA(A) receptors critically depend on the intracellular Cl− concentration ([Cl−]i), which is maintained by a set of transmembrane transporters for Cl−. During neuronal development, but also under several pathophysiological conditions, the prevailing expression of the Cl− loader NKCC1 and the low expression of the Cl− extruder KCC2 causes elevated [Cl−]i, which result in depolarizing GABAergic membrane responses. However, depolarizing GABAergic responses are not necessarily excitatory, as GABA(A) receptors also reduces the input resistance of neurons and thereby shunt excitatory inputs. To summarize our knowledge on the effect of depolarizing GABA responses on neuronal excitability, this review discusses theoretical considerations and experimental studies illustrating the relation between GABA conductances, GABA reversal potential and neuronal excitability. In addition, evidences for the complex spatiotemporal interaction between depolarizing GABAergic and glutamatergic inputs are described. Moreover, mechanisms that influence [Cl−]i beyond the expression of Cl− transporters are presented. And finally, several in vitro and in vivo studies that directly investigated whether GABA mediates excitation or inhibition during early developmental stages are summarized. In summary, these theoretical considerations and experimental evidences suggest that GABA can act as inhibitory neurotransmitter even under conditions that maintain substantial depolarizing membrane responses.
Collapse
Affiliation(s)
- Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Savardi A, Borgogno M, De Vivo M, Cancedda L. Pharmacological tools to target NKCC1 in brain disorders. Trends Pharmacol Sci 2021; 42:1009-1034. [PMID: 34620512 DOI: 10.1016/j.tips.2021.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/27/2021] [Accepted: 09/08/2021] [Indexed: 02/06/2023]
Abstract
The chloride importer NKCC1 and the chloride exporter KCC2 are key regulators of neuronal chloride concentration. A defective NKCC1/KCC2 expression ratio is associated with several brain disorders. Preclinical/clinical studies have shown that NKCC1 inhibition by the United States FDA-approved diuretic bumetanide is a potential therapeutic strategy in preclinical/clinical studies of multiple neurological conditions. However, bumetanide has poor brain penetration and causes unwanted diuresis by inhibiting NKCC2 in the kidney. To overcome these issues, a growing number of studies have reported more brain-penetrating and/or selective bumetanide prodrugs, analogs, and new molecular entities. Here, we review the evidence for NKCC1 pharmacological inhibition as an effective strategy to manage neurological disorders. We also discuss the advantages and limitations of bumetanide repurposing and the benefits and risks of new NKCC1 inhibitors as therapeutic agents for brain disorders.
Collapse
Affiliation(s)
- Annalisa Savardi
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy; Dulbecco Telethon Institute, 00185 Rome, Italy; Molecular Modeling and Drug Discovery Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Marco Borgogno
- Molecular Modeling and Drug Discovery Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Marco De Vivo
- Molecular Modeling and Drug Discovery Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy.
| | - Laura Cancedda
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy; Dulbecco Telethon Institute, 00185 Rome, Italy.
| |
Collapse
|
32
|
Lee KL, Abiraman K, Lucaj C, Ollerhead TA, Brandon NJ, Deeb TZ, Maguire J, Moss SJ. Inhibiting with-no-lysine kinases enhances K+/Cl- cotransporter 2 activity and limits status epilepticus. Brain 2021; 145:950-963. [PMID: 34528073 DOI: 10.1093/brain/awab343] [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] [Received: 01/29/2021] [Revised: 06/25/2021] [Accepted: 08/14/2021] [Indexed: 11/12/2022] Open
Abstract
First-in-line benzodiazepine treatment fails to terminate seizures in about 30% of epilepsy patients, highlighting a need for novel antiseizure strategies. Impaired GABAergic inhibition is key to the development of such benzodiazepine-resistant seizures, as well as the pathophysiology of status epilepticus (SE). It is emerging that reduced or impaired neuronal K+/Cl- cotransporter 2 (KCC2) activity contributes to deficits in γ-aminobutyric acid (GABA)-mediated inhibition and increased seizure vulnerability. The with-no-lysine kinase (WNK)-STE20/SPS1-related proline/alanine-rich (SPAK) kinase signaling pathway inhibits neuronal KCC2 via KCC2-T1007 phosphorylation. A selective WNK kinase inhibitor, WNK463, was recently synthesized by Novartis. Exploiting WNK463, we test the hypothesis that pharmacological WNK inhibition will enhance KCC2 activity, increase the efficacy of GABAergic inhibition, and thereby limit seizure activity in animal models. Immunoprecipitation and Western blot analysis were used to examine WNK463's effects on KCC2-T1007 phosphorylation, in vitro and in vivo. A thallium (Tl+) uptake assay was used in human embryonic kidney (HEK-293) cells expressing KCC2 to test WNK463's effects on KCC2-mediated Tl+ transport. Gramicidin-perforated- and whole-cell patch-clamp recordings in cortical rat neurons were used to examine WNK463's effects on KCC2-mediated Cl- transport. In mouse brain slices (entorhinal cortex), field recordings were utilized to examine WNK463's effects on 4-aminopyridine-induced seizure activity. Last, WNK463 was directly deliver to the mouse hippocampus in vivo and tested in a kainic acid model of diazepam-resistant SE. WNK463 significantly reduces KCC2-T1007 phosphorylation in vitro and in vivo (mice). In human embryonic kidney 293 (HEK-293) cells expressing KCC2, WNK463 greatly enhanced the rates Tl+ transport. However, the drug did not enhance Tl+ transport in cells expressing a KCC2-phospho null T1007 mutant. In cultured rat neurons, WNK463 rapidly reduced intracellular Cl- and consequently hyperpolarized the Cl- reversal potential (EGABA). In mature neurons that were artificially loaded with 30 mM Cl-, WNK463 significantly enhanced KCC2-mediated Cl- export and hyperpolarized EGABA. In a 4-aminopyridine model of acute seizures, WNK463 reduced the frequency and number of seizure-like events (SLEs). Finally, in an in vivo kainic acid (KA) model of diazepam-resistant SE, WNK463 slowed the onset and reduced the severity of KA-induced status epilepticus. Last, WNK463 prevented the development of pharmaco-resistance to diazepam in drug-treated mice. Our findings demonstrate that acute WNK463 treatment potentiates KCC2 activity in neurons and limits seizure burden in two well-established models of seizures and epilepsy. Our work suggests that agents which act to increase KCC2 activity may be useful adjunct therapeutics to alleviate diazepam-resistant SE.
Collapse
Affiliation(s)
- Kathryn L Lee
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111
| | - Krithika Abiraman
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111
| | - Christopher Lucaj
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111.,AstraZeneca-Tufts Laboratory of Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111
| | - Thomas A Ollerhead
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111
| | - Nicholas J Brandon
- Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Boston, MA, USA 02451
| | - Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111.,AstraZeneca-Tufts Laboratory of Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111
| | - Jamie Maguire
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111
| | - Stephen J Moss
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111.,AstraZeneca-Tufts Laboratory of Basic and Translational Neuroscience, Tufts University School of Medicine, Boston, MA, USA 02111.,Department of Neuroscience, Physiology and Pharmacology, University College London, WC16BT, UK
| |
Collapse
|
33
|
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.
Collapse
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.
| |
Collapse
|
34
|
Ragot A, Luhmann HJ, Dipper-Wawra M, Heinemann U, Holtkamp M, Fidzinski P. Pathology-selective antiepileptic effects in the focal freeze-lesion rat model of malformation of cortical development. Exp Neurol 2021; 343:113776. [PMID: 34058228 DOI: 10.1016/j.expneurol.2021.113776] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 05/13/2021] [Accepted: 05/27/2021] [Indexed: 01/29/2023]
Abstract
Malformations of cortical development (MCD) represent a group of rare diseases with severe clinical presentation as epileptic and pharmacoresistant encephalopathies. Morphological studies in tissue from MCD patients have revealed reduced GABAergic efficacy and increased intracellular chloride concentration in neuronal cells as important pathophysiological mechanisms in MCD. Also, in various animal models, alterations of GABAergic inhibition have been postulated as a predominant factor contributing to perilesional hyperexcitability. Along with this line, the NKCC1 inhibitor bumetanide has been postulated as a potential drug for treatment of epilepsy, mediating its antiepileptic effect by reduction of the intracellular chloride and increased inhibitory efficacy of GABAergic transmission. In the present study, we focused on the focal freeze-lesion model of MCD to compare antiepileptic drugs with distinct mechanisms of action, including NKCC1 inhibition by bumetanide. For this purpose, we combined electrophysiological and optical methods in slice preparations and assessed the properties of seizure like events (SLE) induced by 4-aminopyridine. In freeze-lesioned but not control slices, SLE onset was confined to the perilesional area, confirming that this region is hyperexcitable and likely triggers pathological activity. Bumetanide selectively reduced epileptic activity in lesion-containing slices but not in slices from sham-treated control rats. Moreover, bumetanide caused a shift in the SLE onset site away from the perilesional area. In contrast, effects of other antiepileptic drugs including carbamazepine, lacosamide, acezatolamide and zonisamide occurred mostly independently of the lesion and did not result in a shift of the onset region. Our work adds evidence for the functional relevance of chloride homeostasis in the pathophysiology of microgyrus formation as represented in the focal freeze-lesion model. Further studies in different MCD models and human tissue will be required to validate the effects across different MCD subtypes and species and to assess the translational value of our findings.
Collapse
Affiliation(s)
- Aliénor Ragot
- Charité - Universitätsmedizin Berlin, Clinical and Experimental Epileptology, Department of Neurology, Charitéplatz 1, 10117 Berlin, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Matthias Dipper-Wawra
- Charité - Universitätsmedizin Berlin, Clinical and Experimental Epileptology, Department of Neurology, Charitéplatz 1, 10117 Berlin, Germany
| | - Uwe Heinemann
- Charité - Universitätsmedizin Berlin, Institute of Neurophysiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Martin Holtkamp
- Charité - Universitätsmedizin Berlin, Clinical and Experimental Epileptology, Department of Neurology, Charitéplatz 1, 10117 Berlin, Germany; Epilepsy-Center Berlin-Brandenburg, Institute for Diagnostics of Epilepsy, Berlin, Germany
| | - Pawel Fidzinski
- Charité - Universitätsmedizin Berlin, Clinical and Experimental Epileptology, Department of Neurology, Charitéplatz 1, 10117 Berlin, Germany; Epilepsy-Center Berlin-Brandenburg, Institute for Diagnostics of Epilepsy, Berlin, Germany; Berlin Institute of Health at Charité -Universitätsmedizin Berlin, NeuroCure Clinical Research Center, Charitéplatz 1, 10117 Berlin, Germany.
| |
Collapse
|
35
|
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.
Collapse
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
| |
Collapse
|
36
|
A limited role of NKCC1 in telencephalic glutamatergic neurons for developing hippocampal network dynamics and behavior. Proc Natl Acad Sci U S A 2021; 118:2014784118. [PMID: 33782119 DOI: 10.1073/pnas.2014784118] [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] [Indexed: 11/18/2022] Open
Abstract
NKCC1 is the primary transporter mediating chloride uptake in immature principal neurons, but its role in the development of in vivo network dynamics and cognitive abilities remains unknown. Here, we address the function of NKCC1 in developing mice using electrophysiological, optical, and behavioral approaches. We report that NKCC1 deletion from telencephalic glutamatergic neurons decreases in vitro excitatory actions of γ-aminobutyric acid (GABA) and impairs neuronal synchrony in neonatal hippocampal brain slices. In vivo, it has a minor impact on correlated spontaneous activity in the hippocampus and does not affect network activity in the intact visual cortex. Moreover, long-term effects of the developmental NKCC1 deletion on synaptic maturation, network dynamics, and behavioral performance are subtle. Our data reveal a neural network function of NKCC1 in hippocampal glutamatergic neurons in vivo, but challenge the hypothesis that NKCC1 is essential for major aspects of hippocampal development.
Collapse
|
37
|
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.
Collapse
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
| |
Collapse
|
38
|
Doi A, Miyazaki T, Mihara T, Ikeda M, Niikura R, Andoh T, Goto T. CLP290 promotes the sedative effects of midazolam in neonatal rats in a KCC2-dependent manner: A laboratory study in rats. PLoS One 2021; 16:e0248113. [PMID: 33711029 PMCID: PMC7954344 DOI: 10.1371/journal.pone.0248113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 02/22/2021] [Indexed: 11/25/2022] Open
Abstract
Immature neurons dominantly express the Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) rather than the K+-Cl- cotransporter isoform 2 (KCC2). The intracellular chloride ion concentration ([Cl-]i) is higher in immature neurons than in mature neurons; therefore, γ-aminobutyric acid type A (GABAA) receptor activation in immature neurons does not cause chloride ion influx and subsequent hyperpolarization. In our previous work, we found that midazolam, benzodiazepine receptor agonist, causes less sedation in neonatal rats compared to adult rats and that NKCC1 blockade by bumetanide enhances the midazolam-induced sedation in neonatal, but not in adult, rats. These results suggest that GABA receptor activation requires the predominance of KCC2 over NKCC1 to exert sedative effects. In this study, we focused on CLP290, a novel KCC2-selective activator, and found that midazolam administration at 20 mg/kg after oral CLP290 intake significantly prolonged the righting reflex latency even in neonatal rats at postnatal day 7. By contrast, CLP290 alone did not exert sedative effects. Immunohistochemistry showed that midazolam combined with CLP290 decreased the number of phosphorylated cAMP response element-binding protein-positive cells in the cerebral cortex, suggesting that CLP290 reverted the inhibitory effect of midazolam. Moreover, the sedative effect of combined CLP290 and midazolam treatment was inhibited by the administration of the KCC2-selective inhibitor VU0463271, suggesting indirectly that the sedation-promoting effect of CLP290 was mediated by KCC2 activation. To our knowledge, this study is the first report showing the sedation-promoting effect of CLP290 in neonates and providing behavioral and histological evidence that CLP290 reverted the sedative effect of GABAergic drugs through the activation of KCC2. Our data suggest that the clinical application of CLP290 may provide a breakthrough in terms of midazolam-resistant sedation.
Collapse
Affiliation(s)
- Akiko Doi
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Miyazaki
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takahiro Mihara
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Maiko Ikeda
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Ryo Niikura
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomio Andoh
- Department of Anesthesiology, Mizonokuchi Hospital, Teikyo University School of Medicine, Kawasaki, Japan
| | - Takahisa Goto
- Department of Anesthesiology and Critical Care Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| |
Collapse
|
39
|
Kim HR, Rajagopal L, Meltzer HY, Martina M. Depolarizing GABA A current in the prefrontal cortex is linked with cognitive impairment in a mouse model relevant for schizophrenia. SCIENCE ADVANCES 2021; 7:eaba5032. [PMID: 33789887 PMCID: PMC8011979 DOI: 10.1126/sciadv.aba5032] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/12/2021] [Indexed: 05/06/2023]
Abstract
Cognitive impairment in schizophrenia (CIAS) is the most critical predictor of functional outcome. Limited understanding of the cellular mechanisms of CIAS hampers development of more effective treatments. We found that in subchronic phencyclidine (scPCP)-treated mice, an animal model that mimics CIAS, the reversal potential of GABAA currents in pyramidal neurons of the infralimbic prefrontal cortex (ILC) shifts from hyperpolarizing to depolarizing, the result of increased expression of the chloride transporter NKCC1. Further, we found that in scPCP mice, the NKCC1 antagonist bumetanide normalizes GABAA current polarity ex vivo and improves performance in multiple cognitive tasks in vivo. This behavioral effect was mimicked by selective, bilateral, NKCC1 knockdown in the ILC. Thus, we show that depolarizing GABAA currents in the ILC contributes to cognitive impairments in scPCP mice and suggest that bumetanide, an FDA-approved drug, has potential to treat or prevent CIAS and other components of the schizophrenia syndrome.
Collapse
Affiliation(s)
- Haram R Kim
- Department of Physiology, Feinberg School of Medicine, Northwestern University, 300 E. Chicago Avenue, Chicago, IL 60611, USA
| | - Lakshmi Rajagopal
- Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, 300 E. Chicago Avenue, Chicago, IL 60611, USA
| | - Herbert Y Meltzer
- Department of Physiology, Feinberg School of Medicine, Northwestern University, 300 E. Chicago Avenue, Chicago, IL 60611, USA.
- Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, 300 E. Chicago Avenue, Chicago, IL 60611, USA
| | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, 300 E. Chicago Avenue, Chicago, IL 60611, USA.
- Psychiatry and Behavioral Sciences, Feinberg School of Medicine, Northwestern University, 300 E. Chicago Avenue, Chicago, IL 60611, USA
| |
Collapse
|
40
|
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.
Collapse
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.
| |
Collapse
|
41
|
Abstract
The adult brain is the result of a multistages complex neurodevelopmental process involving genetic, molecular and microenvironmental factors as well as diverse patterns of electrical activity. In the postnatal life, immature neuronal circuits undergo an experience-dependent maturation during critical periods of plasticity, but the brain still retains plasticity during adult life. In all these stages, the neurotransmitter GABA plays a pivotal role. In this chapter, we will describe the interaction of 5-HT with GABA in regulating neurodevelopment and plasticity.
Collapse
|
42
|
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.
Collapse
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
| |
Collapse
|
43
|
Wang R, Lin Q. Prolonged ketamine exposure induces enhanced excitatory GABAergic synaptic activity in the anterior cingulate cortex of neonatal rats. Neurosci Lett 2021; 745:135647. [PMID: 33444673 DOI: 10.1016/j.neulet.2021.135647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/06/2021] [Indexed: 11/28/2022]
Abstract
Experimental studies have indicated that prolonged ketamine exposure in neonates at anesthetic doses causes neuronal apoptosis, which contributes to long-term impairments of learning and memory later in life. The neuronal excitotoxicity mediated by compensatory upregulation of N-methyl-d-aspartate receptors (NMDARs) is proposed to be the underlying mechanism. However, this view does not convincingly explain why excitotoxicity-related apoptotic injury develops selectively in immature neurons. We proposed that the GABAA receptors (GABAARs)-mediated excitatory synaptic signaling due to high expression of the Na+-K+-2Cl- co-transporter (NKCC1), occurring during the early neuronal development period, plays a distinct role in the susceptibility of immature neurons to ketamine-induced injury. Using whole-cell patch-clamp recordings from the forebrain slices containing the anterior cingulate cortex, we found that in vivo repeated ketamine administration significantly induced neuronal hyperexcitability in neonatal, but not adolescent, rats. Such hyperexcitability was accompanied by the increase both in GABAAR- and NMDAR-mediated synaptic transmissions. An interference with the NKCC1 by bumetanide treatment completely reversed these enhanced effects of ketamine exposure and blocked GABAAR-mediated postsynaptic current activity. Thus, these findings were significant as they showed, for the first time, that GABAAR-mediated excitatory action may contribute distinctly to neuronal excitotoxic effects of ketamine on immature neurons in the developing brain.
Collapse
Affiliation(s)
- Ruirui Wang
- Department of Psychology, The University of Texas at Arlington, TX, USA
| | - Qing Lin
- Department of Psychology, The University of Texas at Arlington, TX, USA.
| |
Collapse
|
44
|
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.
Collapse
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.
| |
Collapse
|
45
|
Roy AS, Sawrav MSS, Hossain MS, Johura FT, Ahmed SF, Hami I, Islam MK, Al Reza H, Bhuiyan MIH, Bahadur NM, Rahaman MM. In silico identification of potential inhibitors with higher potency than bumetanide targeting NKCC1: An important ion co-transporter to treat neurological disorders. INFORMATICS IN MEDICINE UNLOCKED 2021. [DOI: 10.1016/j.imu.2021.100777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
|
46
|
Virtanen MA, Uvarov P, Hübner CA, Kaila K. NKCC1, an Elusive Molecular Target in Brain Development: Making Sense of the Existing Data. Cells 2020; 9:cells9122607. [PMID: 33291778 PMCID: PMC7761970 DOI: 10.3390/cells9122607] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
Ionotropic GABA transmission is mediated by anion (mainly Cl−)-permeable GABAA receptors (GABAARs). In immature neurons, GABA exerts depolarizing and sometimes functionally excitatory actions, based on active uptake of Cl− by the Na-K-2Cl cotransporter NKCC1. While functional evidence firmly shows NKCC1-mediated ion transport in immature and diseased neurons, molecular detection of NKCC1 in the brain has turned out to be extremely difficult. In this review, we describe the highly inconsistent data that are available on the cell type-specific expression patterns of the NKCC1 mRNA and protein in the CNS. We discuss the major technical caveats, including a lack of knock-out-controlled immunohistochemistry in the forebrain, possible effects of alternative splicing on the binding of antibodies and RNA probes, and the wide expression of NKCC1 in different cell types, which make whole-tissue analyses of NKCC1 useless for studying its neuronal expression. We also review novel single-cell RNAseq data showing that most of the NKCC1 in the adult CNS may, in fact, be expressed in non-neuronal cells, especially in glia. As future directions, we suggest single-cell NKCC1 mRNA and protein analyses and the use of genetically tagged endogenous proteins or systematically designed novel antibodies, together with proper knock-out controls, for the visualization of endogenous NKCC1 in distinct brain cell types and their subcellular compartments.
Collapse
Affiliation(s)
- Mari A. Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Christian A. Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany;
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
- Correspondence: ; Tel.: +358-407256759
| |
Collapse
|
47
|
Androgenic Modulation of the Chloride Transporter NKCC1 Contributes to Age-dependent Isoflurane Neurotoxicity in Male Rats. Anesthesiology 2020; 133:852-866. [PMID: 32930727 DOI: 10.1097/aln.0000000000003437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Cognitive deficits after perinatal anesthetic exposure are well established outcomes in animal models. This vulnerability is sex-dependent and associated with expression levels of the chloride transporters NKCC1 and KCC2. The hypothesis was that androgen signaling, NKCC1 function, and the age of isoflurane exposure are critical for the manifestation of anesthetic neurotoxicity in male rats. METHODS Flutamide, an androgen receptor antagonist, was administered to male rats on postnatal days 2, 4, and 6 before 6 h of isoflurane on postnatal day 7 (ntotal = 26). Spatial and recognition memory were subsequently tested in adulthood. NKCC1 and KCC2 protein levels were measured from cortical lysates by Western blot on postnatal day 7 (ntotal = 20). Bumetanide, an NKCC1 antagonist, was injected immediately before isoflurane exposure (postnatal day 7) to study the effect of NKCC1 inhibition (ntotal = 48). To determine whether male rats remain vulnerable to anesthetic neurotoxicity as juveniles, postnatal day 14 animals were exposed to isoflurane and assessed as adults (ntotal = 30). RESULTS Flutamide-treated male rats exposed to isoflurane successfully navigated the spatial (Barnes maze probe trial F[1, 151] = 78; P < 0.001; mean goal exploration ± SD, 6.4 ± 3.9 s) and recognition memory tasks (mean discrimination index ± SD, 0.09 ± 0.14; P = 0.003), unlike isoflurane-exposed controls. Flutamide changed expression patterns of NKCC1 (mean density ± SD: control, 1.49 ± 0.69; flutamide, 0.47 ± 0.11; P < 0.001) and KCC2 (median density [25th percentile, 75th percentile]: control, 0.23 [0.13, 0.49]; flutamide, 1.47 [1.18,1.62]; P < 0.001). Inhibiting NKCC1 with bumetanide was protective for spatial memory (probe trial F[1, 162] = 6.6; P = 0.011; mean goal time, 4.6 [7.4] s). Delaying isoflurane exposure until postnatal day 14 in males preserved spatial memory (probe trial F[1, 140] = 28; P < 0.001; mean goal time, 6.1 [7.0] s). CONCLUSIONS Vulnerability to isoflurane neurotoxicity is abolished by blocking the androgen receptor, disrupting the function of NKCC1, or delaying the time of exposure to at least 2 weeks of age in male rats. These results support a dynamic role for androgens and chloride transporter proteins in perinatal anesthetic neurotoxicity. EDITOR’S PERSPECTIVE
Collapse
|
48
|
Barnes S, Grove JCR, McHugh CF, Hirano AA, Brecha NC. Horizontal Cell Feedback to Cone Photoreceptors in Mammalian Retina: Novel Insights From the GABA-pH Hybrid Model. Front Cell Neurosci 2020; 14:595064. [PMID: 33328894 PMCID: PMC7672006 DOI: 10.3389/fncel.2020.595064] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 09/24/2020] [Indexed: 01/20/2023] Open
Abstract
How neurons in the eye feed signals back to photoreceptors to optimize sensitivity to patterns of light appears to be mediated by one or more unconventional mechanisms. Via these mechanisms, horizontal cells control photoreceptor synaptic gain and enhance key aspects of temporal and spatial center-surround receptive field antagonism. After the transduction of light energy into an electrical signal in photoreceptors, the next key task in visual processing is the transmission of an optimized signal to the follower neurons in the retina. For this to happen, the release of the excitatory neurotransmitter glutamate from photoreceptors is carefully regulated via horizontal cell feedback, which acts as a thermostat to keep the synaptic transmission in an optimal range during changes to light patterns and intensities. Novel findings of a recently described model that casts a classical neurotransmitter system together with ion transport mechanisms to adjust the alkaline milieu outside the synapse are reviewed. This novel inter-neuronal messaging system carries feedback signals using two separate, but interwoven regulated systems. The complex interplay between these two signaling modalities, creating synaptic modulation-at-a-distance, has obscured it’s being defined. The foundations of our understanding of the feedback mechanism from horizontal cells to photoreceptors have been long established: Horizontal cells have broad receptive fields, suitable for providing surround inhibition, their membrane potential, a function of stimulus intensity and size, regulates inhibition of photoreceptor voltage-gated Ca2+ channels, and strong artificial pH buffering eliminates this action. This review compares and contrasts models of how these foundations are linked, focusing on a recent report in mammals that shows tonic horizontal cell release of GABA activating Cl− and HCO3− permeable GABA autoreceptors. The membrane potential of horizontal cells provides the driving force for GABAR-mediated HCO3− efflux, alkalinizing the cleft when horizontal cells are hyperpolarized by light or adding to their depolarization in darkness and contributing to cleft acidification via NHE-mediated H+ efflux. This model challenges interpretations of earlier studies that were considered to rule out a role for GABA in feedback to cones.
Collapse
Affiliation(s)
- Steven Barnes
- Doheny Eye Institute, Los Angeles, CA, United States.,Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - James C R Grove
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, United States
| | | | - Arlene A Hirano
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States
| | - Nicholas C Brecha
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, United States.,Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
49
|
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.
Collapse
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
| |
Collapse
|
50
|
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.
Collapse
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
| |
Collapse
|