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Spencer KA, Woods CB, Worstman HM, Johnson SC, Ramirez JM, Morgan PG, Sedensky MM. TREK-1 and TREK-2 Knockout Mice Are Not Resistant to Halothane or Isoflurane. Anesthesiology 2023; 139:63-76. [PMID: 37027798 PMCID: PMC10247454 DOI: 10.1097/aln.0000000000004577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
BACKGROUND A variety of molecular targets for volatile anesthetics have been suggested, including the anesthetic-sensitive potassium leak channel, TREK-1. Knockout of TREK-1 is reported to render mice resistant to volatile anesthetics, making TREK-1 channels compelling targets for anesthetic action. Spinal cord slices from mice, either wild type or an anesthetic- hypersensitive mutant, Ndufs4, display an isoflurane-induced outward potassium leak that correlates with their minimum alveolar concentrations and is blocked by norfluoxetine. The hypothesis was that TREK-1 channels conveyed this current and contribute to the anesthetic hypersensitivity of Ndufs4. The results led to evaluation of a second TREK channel, TREK-2, in control of anesthetic sensitivity. METHODS The anesthetic sensitivities of mice carrying knockout alleles of Trek-1 and Trek-2, the double knockout Trek-1;Trek-2, and Ndufs4;Trek-1 were measured. Neurons from spinal cord slices from each mutant were patch clamped to characterize isoflurane-sensitive currents. Norfluoxetine was used to identify TREK-dependent currents. RESULTS The mean values for minimum alveolar concentrations (± SD) between wild type and two Trek-1 knockout alleles in mice (P values, Trek-1 compared to wild type) were compared. For wild type, minimum alveolar concentration of halothane was 1.30% (0.10), and minimum alveolar concentration of isoflurane was 1.40% (0.11); for Trek-1tm1Lex, minimum alveolar concentration of halothane was 1.27% (0.11; P = 0.387), and minimum alveolar concentration of isoflurane was 1.38% (0.09; P = 0.268); and for Trek-1tm1Lzd, minimum alveolar concentration of halothane was 1.27% (0.11; P = 0.482), and minimum alveolar concentration of isoflurane was 1.41% (0.12; P = 0.188). Neither allele was resistant for loss of righting reflex. The EC50 values of Ndufs4;Trek-1tm1Lex did not differ from Ndufs4 (for Ndufs4, EC50 of halothane, 0.65% [0.05]; EC50 of isoflurane, 0.63% [0.05]; and for Ndufs4;Trek-1tm1Lex, EC50 of halothane, 0.58% [0.07; P = 0.004]; and EC50 of isoflurane, 0.61% [0.06; P = 0.442]). Loss of TREK-2 did not alter anesthetic sensitivity in a wild-type or Trek-1 genetic background. Loss of TREK-1, TREK-2, or both did not alter the isoflurane-induced currents in wild-type cells but did cause them to be norfluoxetine insensitive. CONCLUSIONS Loss of TREK channels did not alter anesthetic sensitivity in mice, nor did it eliminate isoflurane-induced transmembrane currents. However, the isoflurane-induced currents are norfluoxetine-resistant in Trek mutants, indicating that other channels may function in this role when TREK channels are deleted. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Kira A Spencer
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
| | - Christian B Woods
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Hailey M Worstman
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
| | - Simon C Johnson
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Applied Sciences, Translational Biosciences, Northumbria University, Ellison A521A, UK (current)
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Neurological Surgery, University of Washington, Seattle, WA, 98105, USA
| | - Philip G Morgan
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
| | - Margaret M Sedensky
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101, USA
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle WA, 98105, USA
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2
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Zheng X, Yang J, Zhu Z, Fang Y, Tian Y, Xie M, Wang W, Liu Y. The Two-Pore Domain Potassium Channel TREK-1 Promotes Blood-Brain Barrier Breakdown and Exacerbates Neuronal Death After Focal Cerebral Ischemia in Mice. Mol Neurobiol 2022; 59:2305-2327. [PMID: 35067892 DOI: 10.1007/s12035-021-02702-5] [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: 09/16/2021] [Accepted: 12/14/2021] [Indexed: 11/24/2022]
Abstract
Earlier studies have shown the neuroprotective role of TWIK-related K+ channel 1 (TREK-1) in global cerebral and spinal cord ischemia, while its function in focal cerebral ischemia has long been debated. This study used TREK-1-deficient mice to directly investigate the role of TREK-1 after focal cerebral ischemia. First, immunofluorescence assays in the mouse cerebral cortex indicated that TREK-1 expression was mostly abundant in astrocytes, neurons, and oligodendrocyte precursor cells but was low in myelinating oligodendrocytes, microglia, or endothelial cells. TREK-1 deficiency did not affect brain weight and morphology or the number of neurons, astrocytes, or microglia but did increase glial fibrillary acidic protein (GFAP) expression in astrocytes of the cerebral cortex. The anatomy of the major cerebral vasculature, number and structure of brain micro blood vessels, and blood-brain barrier integrity were unaltered. Next, mice underwent 60 min of focal cerebral ischemia and 72 h of reperfusion induced by the intraluminal suture method. TREK-1-deficient mice showed less neuronal death, smaller infarction size, milder blood-brain barrier (BBB) breakdown, reduced immune cell invasion, and better neurological function. Finally, the specific pharmacological inhibition of TREK-1 also decreased infarction size and improved neurological function. These results demonstrated that TREK-1 might play a detrimental rather than beneficial role in focal cerebral ischemia, and inhibition of TREK-1 would be a strategy to treat ischemic stroke in the clinic.
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Affiliation(s)
- Xiaolong Zheng
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jun Yang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhou Zhu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yongkang Fang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yeye Tian
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Minjie Xie
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wei Wang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Neurological Diseases of Chinese Ministry of Education, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yang Liu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Two-Pore-Domain Potassium (K 2P-) Channels: Cardiac Expression Patterns and Disease-Specific Remodelling Processes. Cells 2021; 10:cells10112914. [PMID: 34831137 PMCID: PMC8616229 DOI: 10.3390/cells10112914] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/18/2021] [Accepted: 10/22/2021] [Indexed: 12/23/2022] Open
Abstract
Two-pore-domain potassium (K2P-) channels conduct outward K+ currents that maintain the resting membrane potential and modulate action potential repolarization. Members of the K2P channel family are widely expressed among different human cell types and organs where they were shown to regulate important physiological processes. Their functional activity is controlled by a broad variety of different stimuli, like pH level, temperature, and mechanical stress but also by the presence of lipids or pharmacological agents. In patients suffering from cardiovascular diseases, alterations in K2P-channel expression and function have been observed, suggesting functional significance and a potential therapeutic role of these ion channels. For example, upregulation of atrial specific K2P3.1 (TASK-1) currents in atrial fibrillation (AF) patients was shown to contribute to atrial action potential duration shortening, a key feature of AF-associated atrial electrical remodelling. Therefore, targeting K2P3.1 (TASK-1) channels might constitute an intriguing strategy for AF treatment. Further, mechanoactive K2P2.1 (TREK-1) currents have been implicated in the development of cardiac hypertrophy, cardiac fibrosis and heart failure. Cardiovascular expression of other K2P channels has been described, functional evidence in cardiac tissue however remains sparse. In the present review, expression, function, and regulation of cardiovascular K2P channels are summarized and compared among different species. Remodelling patterns, observed in disease models are discussed and compared to findings from clinical patients to assess the therapeutic potential of K2P channels.
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4
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Sakamaki G, Johnson K, Mensinger M, Hmu E, Klein AH. Loss of SUR1 subtype K ATP channels alters antinociception and locomotor activity after opioid administration. Behav Brain Res 2021; 414:113467. [PMID: 34274374 PMCID: PMC11019344 DOI: 10.1016/j.bbr.2021.113467] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 06/07/2021] [Accepted: 07/13/2021] [Indexed: 11/30/2022]
Abstract
Opioid signaling can occur through several downstream mediators and influence analgesia as well as reward mechanisms in the nervous system. KATP channels are downstream targets of the μ opioid receptor and contribute to morphine-induced antinociception. The aim of the present work was to assess the role of SUR1-subtype KATP channels in antinociception and hyperlocomotion of synthetic and semi-synthetic opioids. Adult male and female mice wild-type (WT) and SUR1 deficient (KO) mice were assessed for mechanical and thermal antinociception after administration of either buprenorphine, fentanyl, or DAMGO. Potassium flux was assessed in the dorsal root ganglia and superficial dorsal horn cells in WT and KO mice. Hyperlocomotion was also assessed in WT and KO animals after buprenorphine, fentanyl, or DAMGO administration. SUR1 KO mice had attenuated mechanical antinociception after systemic administration of buprenorphine, fentanyl, and DAMGO. Potassium flux was also attenuated in the dorsal root ganglia and spinal cord dorsal horn cells after acute administration of buprenorphine and fentanyl. Hyperlocomotion after administration of morphine and buprenorphine was potentiated in SUR1 KO mice, but was not seen after administration of fentanyl or DAMGO. These results suggest SUR1-subtype KATP channels mediate the antinociceptive response of several classes of opioids (alkaloid and synthetic/semi-synthetic), but may not contribute to the "drug-seeking" behaviors of all classes of opioids.
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Affiliation(s)
- Gerald Sakamaki
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, Duluth, MN, United States
| | - Kayla Johnson
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, Duluth, MN, United States
| | - Megan Mensinger
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, Duluth, MN, United States
| | - Eindray Hmu
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, Duluth, MN, United States
| | - Amanda H Klein
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota, Duluth, MN, United States.
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Huang W, Ke Y, Zhu J, Liu S, Cong J, Ye H, Guo Y, Wang K, Zhang Z, Meng W, Gao TM, Luhmann HJ, Kilb W, Chen R. TRESK channel contributes to depolarization-induced shunting inhibition and modulates epileptic seizures. Cell Rep 2021; 36:109404. [PMID: 34289346 DOI: 10.1016/j.celrep.2021.109404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/19/2021] [Accepted: 06/23/2021] [Indexed: 11/18/2022] Open
Abstract
Glutamatergic and GABAergic synaptic transmission controls excitation and inhibition of postsynaptic neurons, whereas activity of ion channels modulates neuronal intrinsic excitability. However, it is unclear how excessive neuronal excitation affects intrinsic inhibition to regain homeostatic stability under physiological or pathophysiological conditions. Here, we report that a seizure-like sustained depolarization can induce short-term inhibition of hippocampal CA3 neurons via a mechanism of membrane shunting. This depolarization-induced shunting inhibition (DShI) mediates a non-synaptic, but neuronal intrinsic, short-term plasticity that is able to suppress action potential generation and postsynaptic responses by activated ionotropic receptors. We demonstrate that the TRESK channel significantly contributes to DShI. Disruption of DShI by genetic knockout of TRESK exacerbates the sensitivity and severity of epileptic seizures of mice, whereas overexpression of TRESK attenuates seizures. In summary, these results uncover a type of homeostatic intrinsic plasticity and its underlying mechanism. TRESK might represent a therapeutic target for antiepileptic drugs.
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Affiliation(s)
- Weiyuan Huang
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yue Ke
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Jianping Zhu
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Shuai Liu
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Jin Cong
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Hailin Ye
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yanwu Guo
- The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Kewan Wang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Zhenhai Zhang
- State Key Laboratory of Organ Failure Research, National Clinical Research Center for Kidney Disease, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Center for Precision Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou 510030, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China
| | - Wenxiang Meng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tian-Ming Gao
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China; State Key Laboratory of Organ Failure Research, Collaborative Innovation Center for Brain Science, Southern Medical University, Guangzhou 510515, China
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz 55120, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz 55120, Germany.
| | - Rongqing Chen
- Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China; The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou 510515, China.
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6
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Loss of APP in mice increases thigmotaxis and is associated with elevated brain expression of IL-13 and IP-10/CXCL10. Physiol Behav 2021; 240:113533. [PMID: 34293404 DOI: 10.1016/j.physbeh.2021.113533] [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: 04/16/2021] [Revised: 07/13/2021] [Accepted: 07/16/2021] [Indexed: 11/23/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that leads to memory loss and is often accompanied by increased anxiety. Although AD is a heterogeneous disease, dysregulation of inflammatory pathways is a consistent event. Interestingly, the amyloid precursor protein (APP), which is the source of the amyloid peptide Aβ, is also necessary for the efficient regulation of the innate immune response. Here, we hypothesize that loss of APP function in mice would lead to cognitive loss and anxiety behavior, both of which are typically present in AD, as well as changes in the expression of inflammatory mediators. To test this hypothesis, we performed open field, Y-maze and novel object recognition tests on 12-18-week-old male and female wildtype and AppKO mice to measure thigmotaxis, short-term spatial memory and long-term recognition memory. We then performed a quantitative multiplexed immunoassay to measure levels of 32 cytokines/chemokines associated with AD and anxiety. Our results showed that AppKO mice, compared to wildtype controls, experienced increased thigmotactic behavior but no memory impairments, and this phenotype correlated with increased IP-10 and IL-13 levels. Future studies will determine whether dysregulation of these inflammatory mediators contributes to pathogenesis in AD.
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7
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Mathie A, Veale EL, Golluscio A, Holden RG, Walsh Y. Pharmacological Approaches to Studying Potassium Channels. Handb Exp Pharmacol 2021; 267:83-111. [PMID: 34195873 DOI: 10.1007/164_2021_502] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this review, we consider the pharmacology of potassium channels from the perspective of these channels as therapeutic targets. Firstly, we describe the three main families of potassium channels in humans and disease states where they are implicated. Secondly, we describe the existing therapeutic agents which act on potassium channels and outline why these channels represent an under-exploited therapeutic target with potential for future drug development. Thirdly, we consider the evidence desired in order to embark on a drug discovery programme targeting a particular potassium channel. We have chosen two "case studies": activators of the two-pore domain potassium (K2P) channel TREK-2 (K2P10.1), for the treatment of pain and inhibitors of the voltage-gated potassium channel KV1.3, for use in autoimmune diseases such as multiple sclerosis. We describe the evidence base to suggest why these are viable therapeutic targets. Finally, we detail the main technical approaches available to characterise the pharmacology of potassium channels and identify novel regulatory compounds. We draw particular attention to the Comprehensive in vitro Proarrhythmia Assay initiative (CiPA, https://cipaproject.org ) project for cardiac safety, as an example of what might be both desirable and possible in the future, for ion channel regulator discovery projects.
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Affiliation(s)
- Alistair Mathie
- Medway School of Pharmacy, University of Kent, Kent, UK. .,Medway School of Pharmacy, University of Greenwich, London, UK. .,School of Engineering, Arts, Science and Technology, University of Suffolk, Ipswich, UK.
| | - Emma L Veale
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
| | - Alessia Golluscio
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
| | - Robyn G Holden
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
| | - Yvonne Walsh
- Medway School of Pharmacy, University of Kent, Kent, UK.,Medway School of Pharmacy, University of Greenwich, London, UK
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8
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Mayagoitia K, Shin SD, Rubini M, Siebold L, Wilson CG, Bellinger DL, Figueroa JD, Soriano S. Short-term exposure to dietary cholesterol is associated with downregulation of interleukin-15, reduced thigmotaxis and memory impairment in mice. Behav Brain Res 2020; 393:112779. [PMID: 32585301 DOI: 10.1016/j.bbr.2020.112779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 05/15/2020] [Accepted: 06/16/2020] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative condition associated with loss of memory function, depression and anxiety. The etiology of AD is poorly understood, but both cholesterol dyshomeostasis and dysregulation of the immune system are contributing factors. Current evidence is consistent with a detrimental effect of excess cholesterol on neuroinflammation, both in mouse models of memory loss and in dementia in humans. However, whether the impact of cholesterol on neuroinflammation occurs early and contributes to pathogenesis of the disease or simply reflects a pleiotropic impact at advanced stages of disease is unclear. To explore this question, we measured, in 9-13 week-old mice, cognitive status and changes in brain inflammatory mediators in response to a short-term high-cholesterol diet. We hypothesized that short-term exposure to excess dietary cholesterol would alter the early inflammatory responses associated with cognitive and/or behavioral impairment. We report that short-term exposure to a high-cholesterol diet led to decreased thigmotaxis and short-term spatial memory impairment without affecting long-term recognition memory. Furthermore, cognitive and behavioral phenotypes in these mice were associated with a reduction in interleukin-15 levels in the absence of changes in other inflammatory mediators. Our findings indicate that interleukin-15 may play a role in early stages of cognitive impairment secondary to hypercholesterolemia. Consequently, optimization of interleukin-15 signaling may be a viable effective cognitive therapy in the population susceptible to developing dementia due to risk factors associated with cholesterol dysregulation.
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Affiliation(s)
- Karina Mayagoitia
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Sam D Shin
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Marsilio Rubini
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Lorraine Siebold
- Lawrence D. Longo Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Christopher G Wilson
- Lawrence D. Longo Center for Perinatal Biology, Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Denise L Bellinger
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Johnny D Figueroa
- Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda CA, USA
| | - Salvador Soriano
- Department of Pathology and Human Anatomy, School of Medicine, Loma Linda University, Loma Linda, CA, USA.
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9
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Busserolles J, Lolignier S, Kerckhove N, Bertin C, Authier N, Eschalier A. Replacement of current opioid drugs focusing on MOR-related strategies. Pharmacol Ther 2020; 210:107519. [PMID: 32165137 DOI: 10.1016/j.pharmthera.2020.107519] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 02/24/2020] [Indexed: 12/12/2022]
Abstract
The scarcity and limited risk/benefit ratio of painkillers available on the market, in addition to the opioid crisis, warrant reflection on new innovation strategies. The pharmacopoeia of analgesics is based on products that are often old and derived from clinical empiricism, with limited efficacy or spectrum of action, or resulting in an unsatisfactory tolerability profile. Although they are reference analgesics for nociceptive pain, opioids are subject to the same criticism. The use of opium as an analgesic is historical. Morphine was synthesized at the beginning of the 19th century. The efficacy of opioids is limited in certain painful contexts and these drugs can induce potentially serious and fatal adverse effects. The current North American opioid crisis, with an ever-rising number of deaths by opioid overdose, is a tragic illustration of this. It is therefore legitimate to develop research into molecules likely to maintain or increase opioid efficacy while improving their tolerability. Several avenues are being explored including targeting of the mu opioid receptor (MOR) splice variants, developing biased agonists or targeting of other receptors such as heteromers with MOR. Ion channels acting as MOR effectors, are also targeted in order to offer compounds without MOR-dependent adverse effects. Another route is to develop opioid analgesics with peripheral action or limited central nervous system (CNS) access. Finally, endogenous opioids used as drugs or compounds that modify the metabolism of endogenous opioids (Dual ENKephalinase Inhibitors) are being developed. The aim of the present review is to present these various targets/strategies with reference to current indications for opioids, concerns about their widespread use, particularly in chronic non-cancer pains, and ways of limiting the risk of opioid abuse and misuse.
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Affiliation(s)
- Jérôme Busserolles
- Université Clermont Auvergne, INSERM, CHU, NEURO-DOL Pharmacologie Fondamentale et Clinique de la douleur, F-63000 Clermont-Ferrand, France; Institut ANALGESIA, Faculté de Médecine, F-63000 Clermont-Ferrand, France
| | - Stéphane Lolignier
- Université Clermont Auvergne, INSERM, CHU, NEURO-DOL Pharmacologie Fondamentale et Clinique de la douleur, F-63000 Clermont-Ferrand, France; Institut ANALGESIA, Faculté de Médecine, F-63000 Clermont-Ferrand, France
| | - Nicolas Kerckhove
- Université Clermont Auvergne, INSERM, CHU, NEURO-DOL Pharmacologie Fondamentale et Clinique de la douleur, F-63000 Clermont-Ferrand, France; Institut ANALGESIA, Faculté de Médecine, F-63000 Clermont-Ferrand, France; Observatoire Français des Médicaments Antalgiques (OFMA), French monitoring centre for analgesic drugs, CHU, F-63000 Clermont-Ferrand, France
| | - Célian Bertin
- Université Clermont Auvergne, INSERM, CHU, NEURO-DOL Pharmacologie Fondamentale et Clinique de la douleur, F-63000 Clermont-Ferrand, France; Institut ANALGESIA, Faculté de Médecine, F-63000 Clermont-Ferrand, France; Observatoire Français des Médicaments Antalgiques (OFMA), French monitoring centre for analgesic drugs, CHU, F-63000 Clermont-Ferrand, France
| | - Nicolas Authier
- Université Clermont Auvergne, INSERM, CHU, NEURO-DOL Pharmacologie Fondamentale et Clinique de la douleur, F-63000 Clermont-Ferrand, France; Institut ANALGESIA, Faculté de Médecine, F-63000 Clermont-Ferrand, France; Observatoire Français des Médicaments Antalgiques (OFMA), French monitoring centre for analgesic drugs, CHU, F-63000 Clermont-Ferrand, France
| | - Alain Eschalier
- Université Clermont Auvergne, INSERM, CHU, NEURO-DOL Pharmacologie Fondamentale et Clinique de la douleur, F-63000 Clermont-Ferrand, France; Institut ANALGESIA, Faculté de Médecine, F-63000 Clermont-Ferrand, France.
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10
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Wang W, Kiyoshi CM, Du Y, Taylor AT, Sheehan ER, Wu X, Zhou M. TREK-1 Null Impairs Neuronal Excitability, Synaptic Plasticity, and Cognitive Function. Mol Neurobiol 2020; 57:1332-1346. [PMID: 31728930 PMCID: PMC8808335 DOI: 10.1007/s12035-019-01828-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 10/30/2019] [Indexed: 02/07/2023]
Abstract
TREK-1, a two-pore-domain K+ channel, is highly expressed in the central nervous system. Although aberrant expression of TREK-1 is implicated in cognitive impairment, the cellular and functional mechanism underlying this channelopathy is poorly understood. Here we examined TREK-1 contribution to neuronal morphology, excitability, synaptic plasticity, and cognitive function in mice deficient in TREK-1 expression. TREK-1 immunostaining signal mainly appeared in hippocampal pyramidal neurons, but not in astrocytes. TREK-1 gene knockout (TREK-1 KO) increases dendritic sprouting and the number of immature spines in hippocampal CA1 pyramidal neurons. Functionally, TREK-1 KO increases neuronal excitability and enhances excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs). The increased EPSCs appear to be attributed to an increased release probability of presynaptic glutamate and functional expression of postsynaptic AMPA receptors. TREK-1 KO decreased the paired-pulse ratio and severely occluded the long-term potentiation (LTP) in the CA1 region. These altered synaptic transmission and plasticity are associated with recognition memory deficit in TREK-1 KO mice. Although astrocytic expression of TREK-1 has been reported in previous studies, TREK-1 KO does not alter astrocyte membrane K+ conductance or the syncytial network function in terms of syncytial isopotentiality. Altogether, TREK-1 KO profoundly affects the cellular structure and function of hippocampal pyramidal neurons. Thus, the impaired cognitive function in diseases associated with aberrant expression of TREK-1 should be attributed to the failure of this K+ channel in regulating neuronal morphology, excitability, synaptic transmission, and plasticity.
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Affiliation(s)
- Wei Wang
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Conrad M Kiyoshi
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Yixing Du
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Anne T Taylor
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Erica R Sheehan
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Xiao Wu
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Min Zhou
- Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA.
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11
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Kanda H, Ling J, Tonomura S, Noguchi K, Matalon S, Gu JG. TREK-1 and TRAAK Are Principal K + Channels at the Nodes of Ranvier for Rapid Action Potential Conduction on Mammalian Myelinated Afferent Nerves. Neuron 2019; 104:960-971.e7. [PMID: 31630908 DOI: 10.1016/j.neuron.2019.08.042] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 07/30/2019] [Accepted: 08/27/2019] [Indexed: 12/22/2022]
Abstract
Rapid conduction of nerve impulses is critical in life and relies on action potential (AP) leaps through the nodes of Ranvier (NRs) along myelinated nerves. While NRs are the only sites where APs can be regenerated during nerve conduction on myelinated nerves, ion channel mechanisms underlying the regeneration and conduction of APs at mammalian NRs remain incompletely understood. Here, we show that TREK-1 and TRAAK, the thermosensitive and mechanosensitive two-pore-domain potassium (K2P) channels, are clustered at NRs of rat trigeminal Aβ-afferent nerves with a density over 3,000-fold higher than that on their somas. These K2P channels, but not voltage-gated K+ channels as in other parts of nerves, are required for rapid AP repolarization at the NRs. Furthermore, these channels permit high-speed and high-frequency AP conduction along the myelinated afferent nerves, and loss of function of these channels at NRs retards nerve conduction and impairs sensory behavioral responses in animals.
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Affiliation(s)
- Hirosato Kanda
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jennifer Ling
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Sotatsu Tonomura
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Koichi Noguchi
- Department of Anatomy and Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Jianguo G Gu
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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12
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Mutations in KCNK4 that Affect Gating Cause a Recognizable Neurodevelopmental Syndrome. Am J Hum Genet 2018; 103:621-630. [PMID: 30290154 DOI: 10.1016/j.ajhg.2018.09.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/31/2018] [Indexed: 12/15/2022] Open
Abstract
Aberrant activation or inhibition of potassium (K+) currents across the plasma membrane of cells has been causally linked to altered neurotransmission, cardiac arrhythmias, endocrine dysfunction, and (more rarely) perturbed developmental processes. The K+ channel subfamily K member 4 (KCNK4), also known as TRAAK (TWIK-related arachidonic acid-stimulated K+ channel), belongs to the mechano-gated ion channels of the TRAAK/TREK subfamily of two-pore-domain (K2P) K+ channels. While K2P channels are well known to contribute to the resting membrane potential and cellular excitability, their involvement in pathophysiological processes remains largely uncharacterized. We report that de novo missense mutations in KCNK4 cause a recognizable syndrome with a distinctive facial gestalt, for which we propose the acronym FHEIG (facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, and gingival overgrowth). Patch-clamp analyses documented a significant gain of function of the identified KCNK4 channel mutants basally and impaired sensitivity to mechanical stimulation and arachidonic acid. Co-expression experiments indicated a dominant behavior of the disease-causing mutations. Molecular dynamics simulations consistently indicated that mutations favor sealing of the lateral intramembrane fenestration that has been proposed to negatively control K+ flow by allowing lipid access to the central cavity of the channel. Overall, our findings illustrate the pleiotropic effect of dysregulated KCNK4 function and provide support to the hypothesis of a gating mechanism based on the lateral fenestrations of K2P channels.
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13
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Joseph A, Thuy TTT, Thanh LT, Okada M. Antidepressive and anxiolytic effects of ostruthin, a TREK-1 channel activator. PLoS One 2018; 13:e0201092. [PMID: 30110354 PMCID: PMC6093650 DOI: 10.1371/journal.pone.0201092] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 07/09/2018] [Indexed: 01/02/2023] Open
Abstract
We screened a library of botanical compounds purified from plants of Vietnam for modulators of the activity of a two-pore domain K+ channel, TREK-1, and we identified a hydroxycoumarin-related compound, ostruthin, as an activator of this channel. Ostruthin increased whole-cell TREK-1 channel currents in 293T cells at a low concentration (EC50 = 5.3 μM), and also activity of the TREK-2 channel (EC50 = 3.7 mM). In contrast, ostruthin inhibited other K+ channels, e.g. human ether-à-go-go-related gene (HERG1), inward-rectifier (Kir2.1), voltage-gated (Kv1.4), and two-pore domain (TASK-1) at higher concentrations, without affecting voltage-gated potassium channel (KCNQ1 and 3). We tested the effect of this compound on mouse anxiety- and depression-like behaviors and found anxiolytic activity in the open-field, elevated plus maze, and light/dark box tests. Of note, ostruthin also showed antidepressive effects in the forced swim and tail suspension tests, although previous studies reported that inhibition of TREK-1 channels resulted in an antidepressive effect. The anxiolytic and antidepressive effect was diminished by co-administration of a TREK-1 blocker, amlodipine, indicating the involvement of TREK-1 channels. Administration of ostruthin suppressed the stress-induced increase in anti-c-Fos immunoreactivity in the lateral septum, without affecting immunoreactivity in other mood disorder-related nuclei, e.g. the amygdala, paraventricular nuclei, and dorsal raphe nucleus. Ostruthin may exert its anxiolytic and antidepressive effects through a different mechanism from current drugs.
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Affiliation(s)
- Ancy Joseph
- Department of Physiology, Kansai Medical University, Osaka, Japan
| | - Tran Thi Thu Thuy
- Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Le Tat Thanh
- Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Masayoshi Okada
- Department of Physiology, Kansai Medical University, Osaka, Japan
- Department of Medical Life Science, College of Life Science, Kurashiki University of Science and the Arts, Kurashiki, Okayama, Japan
- * E-mail:
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Hernandez JS, Wainwright ML, Mozzachiodi R. Long-term sensitization training in Aplysia decreases the excitability of a decision-making neuron through a sodium-dependent mechanism. ACTA ACUST UNITED AC 2017; 24:257-261. [PMID: 28507035 PMCID: PMC5435880 DOI: 10.1101/lm.044883.116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 03/31/2017] [Indexed: 11/24/2022]
Abstract
In Aplysia, long-term sensitization (LTS) occurs concurrently with a suppression of feeding. At the cellular level, the suppression of feeding is accompanied by decreased excitability of decision-making neuron B51. We examined the contribution of voltage-gated Na+ and K+ channels to B51 decreased excitability. In a pharmacologically isolated Na+ channels environment, LTS training significantly increased B51 firing threshold, compared with untrained controls. Conversely, in a pharmacologically isolated K+ channels environment, no differences were observed between trained and untrained animals in either amplitude or area of B51 K+-dependent depolarizations. These findings suggest that Na+ channels contribute to the decrease in B51 excitability induced by LTS training.
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Affiliation(s)
- John S Hernandez
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas 78412, USA
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15
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Dadi PK, Vierra NC, Days E, Dickerson MT, Vinson PN, Weaver CD, Jacobson DA. Selective Small Molecule Activators of TREK-2 Channels Stimulate Dorsal Root Ganglion c-Fiber Nociceptor Two-Pore-Domain Potassium Channel Currents and Limit Calcium Influx. ACS Chem Neurosci 2017; 8:558-568. [PMID: 27805811 PMCID: PMC5901755 DOI: 10.1021/acschemneuro.6b00301] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The two-pore-domain potassium (K2P) channel TREK-2 serves to modulate plasma membrane potential in dorsal root ganglia c-fiber nociceptors, which tunes electrical excitability and nociception. Thus, TREK-2 channels are considered a potential therapeutic target for treating pain; however, there are currently no selective pharmacological tools for TREK-2 channels. Here we report the identification of the first TREK-2 selective activators using a high-throughput fluorescence-based thallium (Tl+) flux screen (HTS). An initial pilot screen with a bioactive lipid library identified 11-deoxy prostaglandin F2α as a potent activator of TREK-2 channels (EC50 ≈ 0.294 μM), which was utilized to optimize the TREK-2 Tl+ flux assay (Z' = 0.752). A HTS was then performed with 76 575 structurally diverse small molecules. Many small molecules that selectively activate TREK-2 were discovered. As these molecules were able to activate single TREK-2 channels in excised membrane patches, they are likely direct TREK-2 activators. Furthermore, TREK-2 activators reduced primary dorsal root ganglion (DRG) c-fiber Ca2+ influx. Interestingly, some of the selective TREK-2 activators such as 11-deoxy prostaglandin F2α were found to inhibit the K2P channel TREK-1. Utilizing chimeric channels containing portions of TREK-1 and TREK-2, the region of the TREK channels that allows for either small molecule activation or inhibition was identified. This region lies within the second pore domain containing extracellular loop and is predicted to play an important role in modulating TREK channel activity. Moreover, the selective TREK-2 activators identified in this HTS provide important tools for assessing human TREK-2 channel function and investigating their therapeutic potential for treating chronic pain.
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Affiliation(s)
- Prasanna K. Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Nicholas C. Vierra
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Emily Days
- Institute of Chemical Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Matthew T. Dickerson
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - Paige N. Vinson
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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16
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McCall NM, Kotecki L, Dominguez-Lopez S, Marron Fernandez de Velasco E, Carlblom N, Sharpe AL, Beckstead MJ, Wickman K. Selective Ablation of GIRK Channels in Dopamine Neurons Alters Behavioral Effects of Cocaine in Mice. Neuropsychopharmacology 2017; 42:707-715. [PMID: 27468917 PMCID: PMC5240170 DOI: 10.1038/npp.2016.138] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/23/2016] [Accepted: 07/25/2016] [Indexed: 12/20/2022]
Abstract
The increase in dopamine (DA) neurotransmission stimulated by in vivo cocaine exposure is tempered by G protein-dependent inhibitory feedback mechanisms in DA neurons of the ventral tegmental area (VTA). G protein-gated inwardly rectifying K+ (GIRK/Kir3) channels mediate the direct inhibitory effect of GABAB receptor (GABABR) and D2 DA receptor (D2R) activation in VTA DA neurons. Here we examined the effect of the DA neuron-specific loss of GIRK channels on D2R-dependent regulation of VTA DA neuron excitability and on cocaine-induced, reward-related behaviors. Selective ablation of Girk2 in DA neurons did not alter the baseline excitability of VTA DA neurons but significantly reduced the magnitude of D2R-dependent inhibitory somatodendritic currents and blunted the impact of D2R activation on spontaneous activity and neuronal excitability. Mice lacking GIRK channels in DA neurons exhibited increased locomotor activation in response to acute cocaine administration and an altered locomotor sensitization profile, as well as increased responding for and intake of cocaine in an intravenous self-administration test. These mice, however, showed unaltered cocaine-induced conditioned place preference. Collectively, our data suggest that feedback inhibition to VTA DA neurons, mediated by GIRK channel activation, tempers the locomotor stimulatory effect of cocaine while also modulating the reinforcing effect of cocaine in an operant-based self-administration task.
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Affiliation(s)
- Nora M McCall
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Lydia Kotecki
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - Sergio Dominguez-Lopez
- Department of Physiology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | | | - Nicholas Carlblom
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - Amanda L Sharpe
- Department of Physiology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA,Feik School of Pharmacy, University of the Incarnate Word, San Antonio, TX, USA
| | - Michael J Beckstead
- Department of Physiology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Kevin Wickman
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA,Department of Pharmacology, University of Minnesota, 6-120 Jackson Hall, 321 Church Street S.E., Minneapolis, MN 55455, USA, Tel: +1 612 624 5966, Fax: +1 612 625 8408, E-mail:
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17
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Wang K, Kong X. Isoflurane Preconditioning Induces Neuroprotection by Up-Regulation of TREK1 in a Rat Model of Spinal Cord Ischemic Injury. Biomol Ther (Seoul) 2016; 24:495-500. [PMID: 27469140 PMCID: PMC5012874 DOI: 10.4062/biomolther.2015.206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/03/2016] [Accepted: 05/09/2016] [Indexed: 01/15/2023] Open
Abstract
This study aimed to explore the neuroprotection and mechanism of isoflurane on rats with spinal cord ischemic injury. Total 40 adult male Sprague-Dawley rats were divided into the four groups (n=10). Group A was sham-operation group; group B was ischemia group; group C was isoflurane preconditioning group; group D was isoflurane preconditioning followed by ischemia treatment group. Then the expressions of TWIK-related K⁺ channel 1 (TREK1) in the four groups were detected by immunofluorescent assay, real time-polymerase chain reactions (RT-PCR) and western blot. The primary neurons of rats were isolated and cultured under normal and hypoxic conditions. Besides, the neurons under two conditions were transfected with green fluorescent protein (GFP)-TREK1 and lentivirual to overexpress and silence TREK1. Additionally, the neurons were treated with isoflurane or not. Then caspase-3 activity and cell cycle of neurons under normal and hypoxic conditions were detected. Furthermore, nicotinamide adenine dinucleotide hydrate (NADH) was detected using NAD+/NADH quantification colorimetric kit. Results showed that the mRNA and protein expressions of TREK1 increased significantly in group C and D. In neurons, when TREK1 silenced, isoflurane treatment improved the caspase-3 activity. In hypoxic condition, the caspase-3 activity and sub-G1 cell percentage significantly increased, however, when TREK1 overexpressed the caspase-3 activity and sub-G1 cell percentage decreased significantly. Furthermore, both isoflurane treatment and overexpression of TREK1 significantly decreased NADH. In conclusion, isoflurane-induced neuroprotection in spinal cord ischemic injury may be associated with the up-regulation of TREK1.
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Affiliation(s)
- Kun Wang
- Department of Anesthesiology, Jining No.1 People's Hospital, Jining, Shandong 272011, China
| | - Xiangang Kong
- Department of Anesthesiology, Jining No.1 People's Hospital, Jining, Shandong 272011, China
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18
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Abstract
This review attempts to give a concise and up-to-date overview on the role of potassium channels in epilepsies. Their role can be defined from a genetic perspective, focusing on variants and de novo mutations identified in genetic studies or animal models with targeted, specific mutations in genes coding for a member of the large potassium channel family. In these genetic studies, a demonstrated functional link to hyperexcitability often remains elusive. However, their role can also be defined from a functional perspective, based on dynamic, aggravating, or adaptive transcriptional and posttranslational alterations. In these cases, it often remains elusive whether the alteration is causal or merely incidental. With ∼80 potassium channel types, of which ∼10% are known to be associated with epilepsies (in humans) or a seizure phenotype (in animals), if genetically mutated, a comprehensive review is a challenging endeavor. This goal may seem all the more ambitious once the data on posttranslational alterations, found both in human tissue from epilepsy patients and in chronic or acute animal models, are included. We therefore summarize the literature, and expand only on key findings, particularly regarding functional alterations found in patient brain tissue and chronic animal models.
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Affiliation(s)
- Rüdiger Köhling
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock 18057, Germany
| | - Jakob Wolfart
- Oscar Langendorff Institute of Physiology, University of Rostock, Rostock 18057, Germany
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19
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Yang C, Zhang X, Guo Y, Meng F, Sachs F, Guo J. Mechanical dynamics in live cells and fluorescence-based force/tension sensors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1889-904. [PMID: 25958335 DOI: 10.1016/j.bbamcr.2015.05.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 04/07/2015] [Accepted: 05/01/2015] [Indexed: 01/13/2023]
Abstract
Three signaling systems play the fundamental roles in modulating cell activities: chemical, electrical, and mechanical. While the former two are well studied, the mechanical signaling system is still elusive because of the lack of methods to measure structural forces in real time at cellular and subcellular levels. Indeed, almost all biological processes are responsive to modulation by mechanical forces that trigger dispersive downstream electrical and biochemical pathways. Communication among the three systems is essential to make cells and tissues receptive to environmental changes. Cells have evolved many sophisticated mechanisms for the generation, perception and transduction of mechanical forces, including motor proteins and mechanosensors. In this review, we introduce some background information about mechanical dynamics in live cells, including the ubiquitous mechanical activity, various types of mechanical stimuli exerted on cells and the different mechanosensors. We also summarize recent results obtained using genetically encoded FRET (fluorescence resonance energy transfer)-based force/tension sensors; a new technique used to measure mechanical forces in structural proteins. The sensors have been incorporated into many specific structural proteins and have measured the force gradients in real time within live cells, tissues, and animals.
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Affiliation(s)
- Chao Yang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China
| | - Xiaohan Zhang
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China
| | - Yichen Guo
- The University of Alabama, Tuscaloosa, AL, 35401, USA
| | - Fanjie Meng
- Physiology and Biophysics Department, Center for Single Molecule Studies, University at Buffalo, The State University of New York at Buffalo, Buffalo, NY, 14214, USA
| | - Frederick Sachs
- Physiology and Biophysics Department, Center for Single Molecule Studies, University at Buffalo, The State University of New York at Buffalo, Buffalo, NY, 14214, USA
| | - Jun Guo
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China.
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20
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Bandulik S, Tauber P, Lalli E, Barhanin J, Warth R. Two-pore domain potassium channels in the adrenal cortex. Pflugers Arch 2015; 467:1027-42. [PMID: 25339223 PMCID: PMC4428839 DOI: 10.1007/s00424-014-1628-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 12/31/2022]
Abstract
The physiological control of steroid hormone secretion from the adrenal cortex depends on the function of potassium channels. The "two-pore domain K(+) channels" (K2P) TWIK-related acid sensitive K(+) channel 1 (TASK1), TASK3, and TWIK-related K(+) channel 1 (TREK1) are strongly expressed in adrenocortical cells. They confer a background K(+) conductance to these cells which is important for the K(+) sensitivity as well as for angiotensin II and adrenocorticotropic hormone-dependent stimulation of aldosterone and cortisol synthesis. Mice with single deletions of the Task1 or Task3 gene as well as Task1/Task3 double knockout mice display partially autonomous aldosterone synthesis. It appears that TASK1 and TASK3 serve different functions: TASK1 affects cell differentiation and prevents expression of aldosterone synthase in the zona fasciculata, while TASK3 controls aldosterone secretion in glomerulosa cells. TREK1 is involved in the regulation of cortisol secretion in fasciculata cells. These data suggest that a disturbed function of K2P channels could contribute to adrenocortical pathologies in humans.
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Affiliation(s)
- Sascha Bandulik
- Medical Cell Biology, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany,
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21
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The role of K₂p channels in anaesthesia and sleep. Pflugers Arch 2014; 467:907-16. [PMID: 25482669 PMCID: PMC4428837 DOI: 10.1007/s00424-014-1654-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/11/2014] [Accepted: 11/12/2014] [Indexed: 12/20/2022]
Abstract
Tandem two-pore potassium channels (K2Ps) have widespread expression in the central nervous system and periphery where they contribute to background membrane conductance. Some general anaesthetics promote the opening of some of these channels, enhancing potassium currents and thus producing a reduction in neuronal excitability that contributes to the transition to unconsciousness. Similarly, these channels may be recruited during the normal sleep-wake cycle as downstream effectors of wake-promoting neurotransmitters such as noradrenaline, histamine and acetylcholine. These transmitters promote K2P channel closure and thus an increase in neuronal excitability. Our understanding of the roles of these channels in sleep and anaesthesia has been largely informed by the study of mouse K2P knockout lines and what is currently predicted by in vitro electrophysiology and channel structure and gating.
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22
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Role of the TREK2 potassium channel in cold and warm thermosensation and in pain perception. Pain 2014; 155:2534-2544. [DOI: 10.1016/j.pain.2014.09.013] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/29/2014] [Accepted: 09/11/2014] [Indexed: 12/12/2022]
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Abstract
This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, Flushing, NY 11367, United States.
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24
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Morales E, Groom A, Lawlor DA, Relton CL. DNA methylation signatures in cord blood associated with maternal gestational weight gain: results from the ALSPAC cohort. BMC Res Notes 2014; 7:278. [PMID: 24886386 PMCID: PMC4108052 DOI: 10.1186/1756-0500-7-278] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/10/2014] [Indexed: 12/17/2022] Open
Abstract
Background Epigenetic changes could mediate the association of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) with adverse offspring outcomes. However, studies in humans are lacking. Here, we examined the association of maternal pre-pregnancy BMI and GWG in different periods of pregnancy with cytosine-guanine (CpG) dinucleotide site methylation differences in newborn cord blood DNA from 88 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort using the Illumina GoldenGate Panel I. Pyrosequencing was used for validation of the top associated locus and for replication in 170 non-overlapping mother-offspring pairs from the ALSPAC cohort. Results After correction for multiple testing greater GWG in early pregnancy (between 0 to 18 weeks of gestation) was associated with increased DNA methylation levels in four CpG sites at MMP7, KCNK4, TRPM5 and NFKB1 genes (difference in methylation >5% per 400 g/week greater GWG) (q values 0.023 -0.065). Pre-pregnancy BMI and GWG in mid- or late pregnancy were not associated with differential DNA methylation at any CpG site. Pyrosequencing showed that greater GWG in early pregnancy was associated with increased DNA methylation levels at the top associated CpG site at MMP7, although association did not reach statistical significance (p = 0.302). Greater GWG in mid- (p = 0.167) and late-pregnancy (p = 0.037) were also associated with increased DNA methylation levels at the MMP7 CpG site. In addition, newborns of mothers who exceeded the IoM-recommended GWG had higher DNA methylation levels at the MMP7 CpG site than those of mothers with IoM-recommended GWG (p = 0.080). We failed to replicate findings. Conclusions Greater GWG in early pregnancy was associated with increased methylation at CpG sites at MMP7, KCNK4, TRPM5 and NFKB1 genes in offspring cord blood DNA. The specific association of GWG in early pregnancy with the top associated CpG site at MMP7 was not validated using Pyrosequencing and it did not replicate. However, given the potential functional relevancy of the four identified loci, we advocate further exploration of them in larger studies.
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Affiliation(s)
| | | | | | - Caroline L Relton
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, NE1 3BZ, Tyne and Wear, UK.
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Devilliers M, Busserolles J, Lolignier S, Deval E, Pereira V, Alloui A, Christin M, Mazet B, Delmas P, Noel J, Lazdunski M, Eschalier A. Activation of TREK-1 by morphine results in analgesia without adverse side effects. Nat Commun 2013; 4:2941. [DOI: 10.1038/ncomms3941] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/15/2013] [Indexed: 12/26/2022] Open
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Tong L, Cai M, Huang Y, Zhang H, Su B, Li Z, Dong H. Activation of K(2)P channel-TREK1 mediates the neuroprotection induced by sevoflurane preconditioning. Br J Anaesth 2013; 113:157-67. [PMID: 24154701 PMCID: PMC4062297 DOI: 10.1093/bja/aet338] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background Preconditioning with volatile anaesthetic agents induces tolerance to focal cerebral ischaemia, although the underlying mechanisms have not been clearly defined. The present study analyses whether TREK-1, a two-pore domain K+ channel and target for volatile anaesthetics, plays a role in mediating neuroprotection by sevoflurane. Methods Differentiated SH-SY5Y cells were preconditioning with sevoflurane and challenged by oxygen–glucose deprivation (OGD). Cell viability and expression of caspase-3 and TREK-1 were evaluated. Rats that were preconditioned with sevoflurane were subjected to middle cerebral artery occlusion (MCAO), and the expression of TREK-1 protein and mRNA was analysed. Neurological scores were evaluated and infarction volume was examined. Results Sevoflurane preconditioning reduced cell death in differentiated SH-SY5Y cells challenged by OGD. Sevoflurane preconditioning reduced infarct volume and improved neurological outcome in rats subjected to MCAO. Sevoflurane preconditioning increased levels of TREK-1 mRNA and protein. Knockdown of TREK-1 significantly attenuated sevoflurane preconditioning-induced neuroprotective effects in vitro and in vivo. Conclusions Sevoflurane preconditioning-induced neuroprotective effects against transient cerebral ischaemic injuries involve TREK-1 channels. These results suggest a novel mechanism for sevoflurane preconditioning-induced tolerance to focal cerebral ischaemia.
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Affiliation(s)
- L Tong
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
| | - M Cai
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
| | - Y Huang
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
| | - H Zhang
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
| | - B Su
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
| | - Z Li
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
| | - H Dong
- Department of Anesthesiology, Xijing Hospital, Xi'an, Shanxi 710032, China
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