1
|
Yakhnitsa V, Thompson J, Ponomareva O, Ji G, Kiritoshi T, Mahimainathan L, Molehin D, Pruitt K, Neugebauer V. Dysfunction of Small-Conductance Ca 2+-Activated Potassium (SK) Channels Drives Amygdala Hyperexcitability and Neuropathic Pain Behaviors: Involvement of Epigenetic Mechanisms. Cells 2024; 13:1055. [PMID: 38920682 PMCID: PMC11201618 DOI: 10.3390/cells13121055] [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: 04/29/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024] Open
Abstract
Neuroplasticity in the amygdala and its central nucleus (CeA) is linked to pain modulation and pain behaviors, but cellular mechanisms are not well understood. Here, we addressed the role of small-conductance Ca2+-activated potassium (SK) channels in pain-related amygdala plasticity. The facilitatory effects of the intra-CeA application of an SK channel blocker (apamin) on the pain behaviors of control rats were lost in a neuropathic pain model, whereas an SK channel activator (NS309) inhibited pain behaviors in neuropathic rats but not in sham controls, suggesting the loss of the inhibitory behavioral effects of amygdala SK channels. Brain slice electrophysiology found hyperexcitability of CeA neurons in the neuropathic pain condition due to the loss of SK channel-mediated medium afterhyperpolarization (mAHP), which was accompanied by decreased SK2 channel protein and mRNA expression, consistent with a pretranscriptional mechanisms. The underlying mechanisms involved the epigenetic silencing of the SK2 gene due to the increased DNA methylation of the CpG island of the SK2 promoter region and the change in methylated CpG sites in the CeA in neuropathic pain. This study identified the epigenetic dysregulation of SK channels in the amygdala (CeA) as a novel mechanism of neuropathic pain-related plasticity and behavior that could be targeted to control abnormally enhanced amygdala activity and chronic neuropathic pain.
Collapse
Affiliation(s)
- Vadim Yakhnitsa
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Jeremy Thompson
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Olga Ponomareva
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Guangchen Ji
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Takaki Kiritoshi
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Lenin Mahimainathan
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Deborah Molehin
- Department of Immunology and Molecular Microbiology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Kevin Pruitt
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Volker Neugebauer
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Center of Excellence for Translational Neuroscience and Therapeutics, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| |
Collapse
|
2
|
Zhong H, Ran X, Chen B, Xiong Y, Yu X. Apamin, an SK2 Inhibitor, Attenuated Neonatal Sevoflurane Exposures Caused Cognitive Deficits in Mice through the Regulation of Hippocampal Neuroinflammation. ACS Chem Neurosci 2023; 14:3409-3417. [PMID: 37647501 DOI: 10.1021/acschemneuro.3c00310] [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] [Indexed: 09/01/2023] Open
Abstract
Cognitive dysfunction induced by anesthesia in the infant is a crucial clinical issue that is still being debated and the focus of concern for the parents. However, the mechanism of cognitive decline caused by anesthesia and the corresponding treatment methods remain unclear. Postnatal day 7 (PND7) C57BL/6 mice included in the study were randomly divided into a control group (Control), a group with repeated exposure to sevoflurane (Sevo), and an Apamin intervention group (Sevo + Apamin). Apamin (0.5 μL at the concentration of 100 nmol/L) was injected into the bilateral hippocampus of mice. qRT-PCR, enzyme-linked immunosorbent assay (ELISA), and western blotting assay were used to evaluate the protein levels in the hippocampus. Object location memory (OLM) and novel object recognition (NOR) tasks, as well as elevated plus maze and contextual and cued fear conditioning tasks were used to evaluate the cognitive function of mice. Apamin mitigated sevoflurane-induced cognitive impairment of mice, sevoflurane-induced neuronal injury, and sevoflurane-induced activation of microglial in the hippocampus of the mice. Apamin inhibited M1-type polarization but promoted M2-type polarization of microglia after neonatal sevoflurane exposures in the hippocampus. In conclusion, Apamin attenuates neonatal sevoflurane exposures that cause cognitive deficits in mice through regulating hippocampal neuroinflammation.
Collapse
Affiliation(s)
- Heying Zhong
- Department of Anesthesiology, Affiliated Huadu Hospital, Southern Medical University (People's Hospital of Huadu District), Guangzhou 510000, Guangdong, China
| | - Xiaojuan Ran
- School of Basic Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang 550003, Guizhou, China
| | - Bin Chen
- Department of Anesthesiology, Zunyi Medical University, Zunyi 563000, Guizhou, China
| | - Yiqiang Xiong
- Department of Anesthesiology, Zunyi Medical University, Zunyi 563000, Guizhou, China
| | - Xiangdi Yu
- Department of Anesthesiology, Guizhou Provincial People's Hospital, No. 83 Zhongshan Road, Nanming District, Guiyang 550003, Guizhou, China
| |
Collapse
|
3
|
Mlayah-Bellalouna S, Aissaoui-Zid D, Chantome A, Jebali J, Souid S, Ayedi E, Mejdoub H, Belghazi M, Marrakchi N, Essafi-Benkhadir K, Vandier C, Srairi-Abid N. Insights into the mechanisms governing P01 scorpion toxin effect against U87 glioblastoma cells oncogenesis. Front Pharmacol 2023; 14:1203247. [PMID: 37426811 PMCID: PMC10326281 DOI: 10.3389/fphar.2023.1203247] [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: 04/10/2023] [Accepted: 06/12/2023] [Indexed: 07/11/2023] Open
Abstract
The emerging concept of small conductance Ca2+-activated potassium channels (SKCa) as pharmacological target for cancer treatment has significantly increased in recent years. In this study, we isolated the P01 toxin from Androctonus australis (Aa) scorpion venom and investigated its effect on biological properties of glioblastoma U87, breast MDA-MB231 and colon adenocarcinoma LS174 cancer cell lines. Our results showed that P01 was active only on U87 glioblastoma cells. It inhibited their proliferation, adhesion and migration with IC50 values in the micromolar range. We have also shown that P01 reduced the amplitude of the currents recorded in HEK293 cells expressing SK2 channels with an IC50 value of 3 pM, while it had no effect on those expressing SK3 channels. The investigation of the SKCa channels expression pattern showed that SK2 transcripts were expressed differently in the three cancer cell lines. Particularly, we highlighted the presence of SK2 isoforms in U87 cells, which could explain and rely on the specific activity of P01 on this cell line. These experimental data highlighted the usefulness of scorpion peptides to decipher the role of SKCa channels in the tumorigenesis process, and develop potential therapeutic molecules targeting glioblastoma with high selectivity.
Collapse
Affiliation(s)
- Saoussen Mlayah-Bellalouna
- LR20IPT01 Biomolécules, Venins et Application Théranostique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Dorra Aissaoui-Zid
- LR20IPT01 Biomolécules, Venins et Application Théranostique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Aurelie Chantome
- N2C UMR 1069, Institut national de la santé et de la recherche médicale, University of Tours, Tours, France
| | - Jed Jebali
- LR20IPT01 Biomolécules, Venins et Application Théranostique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Soumaya Souid
- LR16IPT04 Laboratoire d’Epidémiologie Moléculaire et Pathologie Expérimentale, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Emna Ayedi
- LR20IPT01 Biomolécules, Venins et Application Théranostique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Hafedh Mejdoub
- USCR Séquenceur de Protéines, Faculté des Sciences de Sfax, Route de Soukra, Sfax, Tunisia
| | - Maya Belghazi
- Aix Marseille Université, CNRS, Plateforme Protéomique, IMM FR3479, Marseille Protéomique (MaP), Marseille, France
| | - Naziha Marrakchi
- LR20IPT01 Biomolécules, Venins et Application Théranostique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Khadija Essafi-Benkhadir
- LR16IPT04 Laboratoire d’Epidémiologie Moléculaire et Pathologie Expérimentale, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Christophe Vandier
- N2C UMR 1069, Institut national de la santé et de la recherche médicale, University of Tours, Tours, France
| | - Najet Srairi-Abid
- LR20IPT01 Biomolécules, Venins et Application Théranostique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| |
Collapse
|
4
|
Wu X, Yan Q, Liu L, Xue X, Yao W, Li X, Li W, Ding S, Xia Y, Zhang D, Zhu F. Domesticated HERV-W env contributes to the activation of the small conductance Ca 2+-activated K + type 2 channels via decreased 5-HT4 receptor in recent-onset schizophrenia. Virol Sin 2023; 38:9-22. [PMID: 36007838 PMCID: PMC10006216 DOI: 10.1016/j.virs.2022.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022] Open
Abstract
The human endogenous retroviruses type W family envelope (HERV-W env) gene is located on chromosome 7q21-22. Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase calcium influx. Additionally, the 5-HTergic system and particularly 5-hydroxytryptamine (5-HT) receptors play a prominent role in the pathogenesis and treatment of schizophrenia. 5-hydroxytryptamine receptor 4 (5-HT4R) agonist can block calcium channels. However, the underlying relationship between HERV-W env and 5-HT4R in the etiology of schizophrenia has not been revealed. Here, we used enzyme-linked immunosorbent assay to detect the concentration of HERV-W env and 5-HT4R in the plasma of patients with schizophrenia and we found that there were decreased levels of 5-HT4R and a negative correlation between 5-HT4R and HERV-W env in schizophrenia. Overexpression of HERV-W env decreased the transcription and protein levels of 5-HT4R but increased small conductance Ca2+-activated K+ type 2 channels (SK2) expression levels. Further studies revealed that HERV-W env could interact with 5-HT4R. Additionally, luciferase assay showed that an essential region (-364 to -176 from the transcription start site) in the SK2 promoter was required for HERV-W env-induced SK2 expression. Importantly, 5-HT4R participated in the regulation of SK2 expression and promoter activity. Electrophysiological recordings suggested that HERV-W env could increase SK2 channel currents and the increase of SK2 currents was inhibited by 5-HT4R. In conclusion, HERV-W env could activate SK2 channels via decreased 5-HT4R, which might exhibit a novel mechanism for HERV-W env to influence neuronal activity in schizophrenia.
Collapse
Affiliation(s)
- Xiulin Wu
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Qiujin Yan
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | | | - Xing Xue
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Wei Yao
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Xuhang Li
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Wenshi Li
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Shuang Ding
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yaru Xia
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Dongyan Zhang
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China
| | - Fan Zhu
- State Key Laboratory of Virology and Department of Medical Microbiology, School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, China; Hubei Province Key Laboratory of Allergy & Immunology, Wuhan University, Wuhan, 430071, China.
| |
Collapse
|
5
|
Park J, Jang KM, Park KK. Effects of Apamin on MPP +-Induced Calcium Overload and Neurotoxicity by Targeting CaMKII/ERK/p65/STAT3 Signaling Pathways in Dopaminergic Neuronal Cells. Int J Mol Sci 2022; 23:ijms232315255. [PMID: 36499581 PMCID: PMC9736188 DOI: 10.3390/ijms232315255] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/19/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD), a neurodegenerative disorder, is characterized by the loss of dopaminergic (DA) neurons. The pathogenesis of PD is associated with several factors including oxidative stress, inflammation, and mitochondrial dysfunction. Ca2+ signaling plays a vital role in neuronal signaling and altered Ca2+ homeostasis has been implicated in many neuronal diseases including PD. Recently, we reported that apamin (APM), a selective antagonist of the small-conductivity Ca2+-activated K+ (SK) channel, suppresses neuroinflammatory response. However, the mechanism(s) underlying the vulnerability of DA neurons were not fully understood. In this study, we investigated whether APM affected 1-methyl-4-phenyl pyridinium (MPP+)-mediated neurotoxicity in SH-SY5Y cells and rat embryo primary mesencephalic neurons. We found that APM decreased Ca2+ overload arising from MPP+-induced neurotoxicity response through downregulating the level of CaMKII, phosphorylation of ERK, and translocation of nuclear factor NFκB/signal transducer and activator of transcription (STAT)3. Furthermore, we showed that the correlation of MPP+-mediated Ca2+ overload and ERK/NFκB/STAT3 in the neurotoxicity responses, and dopaminergic neuronal cells loss, was verified through inhibitors. Our findings showed that APM might prevent loss of DA neurons via inhibition of Ca2+-overload-mediated signaling pathway and provide insights regarding the potential use of APM in treating neurodegenerative diseases.
Collapse
Affiliation(s)
- Jihyun Park
- Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu 42472, Republic of Korea
| | - Kyung Mi Jang
- Department of Pediatrics, College of Medicine, Yeungnam University, Daegu 42415, Republic of Korea
| | - Kwan-Kyu Park
- Department of Pathology, College of Medicine, Catholic University of Daegu, Daegu 42472, Republic of Korea
- Correspondence: ; Tel.: +82-53-650-4149
| |
Collapse
|
6
|
Corbett BF, Urban K, Luz S, Yan J, Arner J, Bhatnagar S. Sex differences in electrophysiological properties and voltage-gated ion channel expression in the paraventricular thalamic nucleus following repeated stress. Biol Sex Differ 2022; 13:51. [PMID: 36163074 PMCID: PMC9513901 DOI: 10.1186/s13293-022-00460-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Background Habituation to repeated stress refers to a progressive reduction in the stress response following multiple exposures to the same, predictable stressor. We previously demonstrated that the posterior division of the paraventricular thalamic nucleus (pPVT) nucleus regulates habituation to 5 days of repeated restraint stress in male rats. Compared to males, female rats display impaired habituation to 5 days of restraint. To better understand how activity of pPVT neurons is differentially impacted in stressed males and females, we examined the electrophysiological properties of pPVT neurons under baseline conditions or following restraint. Methods Adult male and female rats were exposed to no stress (handling only), a single period of 30 min restraint or 5 daily exposures to 30 min restraint. 24 h later, pPVT tissue was prepared for recordings. Results We report here that spontaneous excitatory post-synaptic current (sEPSC) amplitude was increased in males, but not females, following restraint. Furthermore, resting membrane potential of pPVT neurons was more depolarized in males. This may be partially due to reduced potassium leakage in restrained males as input resistance was increased in male, but not female, rats 24 h following 1 or 5 days of 30-min restraint. Reduced potassium efflux during action potential firing also occurred in males following a single restraint as action potential half-width was increased following a single restraint. Restraint had limited effects on electrophysiological properties in females, although the mRNA for 10 voltage-gated ion channel subunits was altered in the pPVT of female rats. Conclusions The results suggest that restraint-induced changes in pPVT activation promote habituation in males. These findings are the first to describe a sexual dimorphism in stress-induced electrophysiological properties and voltage-gated ion channel expression in the pPVT. These results may explain, at least in part, why habituation to 5 days of restraint is disrupted in female rats. Male, but not female, pPVT neurons display increases in EPSC amplitude and decay time 24 h following one and five restraints. Input resistance is increased 24 h following one and five restraints in male, but not female, pPVT neurons. Afterhyperpolarization potential is greater in pPVT neurons of females compared to males, regardless of restraint. Restraint alters the expression of 10 voltage-gated ion channel transcripts in the pPVT of females, but only 3 in males.
Collapse
Affiliation(s)
- Brian F Corbett
- Department of Biology, Rutgers, The State University of New Jersey, Camden, NJ, USA
| | - Kimberly Urban
- Center for Stress Neurobiology, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sandra Luz
- Center for Stress Neurobiology, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jason Yan
- Center for Stress Neurobiology, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jay Arner
- Center for Stress Neurobiology, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Seema Bhatnagar
- Center for Stress Neurobiology, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, PA, USA. .,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
7
|
Daniel NH, Aravind A, Thakur P. Are ion channels potential therapeutic targets for Parkinson's disease? Neurotoxicology 2021; 87:243-257. [PMID: 34699791 DOI: 10.1016/j.neuro.2021.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 01/31/2023]
Abstract
Parkinson's disease (PD) is primarily associated with the progressive neurodegeneration of the dopaminergic neurons in the substantia nigra region of the brain. The resulting motor symptoms are managed with the help of dopamine replacement therapies. However, these therapeutics do not prevent the neurodegeneration underlying the disease and therefore lose their effectiveness in managing disease symptoms over time. Thus, there is an urgent need to develop newer therapeutics for the benefit of patients. The release of dopamine and the firing activity of substantia nigra neurons is regulated by several ion channels that act in concert. Dysregulations of these channels cause the aberrant movement of various ions in the intracellular milieu. This eventually leads to disruption of intracellular signalling cascades, alterations in cellular homeostasis, and bioenergetic deficits. Therefore, ion channels play a central role in driving the high vulnerability of dopaminergic neurons to degenerate during PD. Targeting ion channels offers an attractive mechanistic strategy to combat the process of neurodegeneration. In this review, we highlight the evidence pointing to the role of various ion channels in driving the PD processes. In addition, we also discuss the various drugs or compounds that target the ion channels and have shown neuroprotective potential in the in-vitro and in-vivo models of PD. We also discuss the current clinical status of various drugs targeting the ion channels in the context of PD.
Collapse
Affiliation(s)
- Neha Hanna Daniel
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India
| | - Ananya Aravind
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India
| | - Poonam Thakur
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India.
| |
Collapse
|
8
|
Chen H, Xia F, Chen X, Cai Y, Jin Z. Ablation of small conductance calcium-activated potassium type-2 channel (SK 2) delays occurrence of bupivacaine-induced cardiotoxicity in isolated mouse hearts. Hum Exp Toxicol 2021; 40:464-471. [PMID: 32909839 DOI: 10.1177/0960327120958102] [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] [Indexed: 11/17/2022]
Abstract
Bupivacaine is frequently used for conducting regional anesthesia. When accidentally injected or excessively absorbed into circulation, bupivacaine can induce severe arrhythmia and potentially lead to cardiac arrest. The specific mechanisms underlying this cardiotoxicity, however, remain to be clarified. We transfected HEK-293 cells to express the small conductance calcium-activated potassium type-2 channel (SK2), and used a whole-cell patch clamp method in order to explore how bupivacaine affected these channels. We subsequently used SK2 knockout mice to explore the relevance of SK2 channels in bupivacaine-induced cardiotoxicity in isolating mouse hearts, mounting them on a Langendorff apparatus, and perfusing them with bupivacaine. Using this system, arrhythmia, asystole, and cardiac functions were monitored. We observed dose-dependent inhibition of SK2 channels by bupivacaine: half-maximal inhibitory concentration (IC50) value = 18.6 μM (95% CI 10.8-32.1). When SK2 knockout (SK2 -/-) or wild-type (WT) mice were perfused with Krebs-Henseleit buffer (KHB), we did not observe any instances of arrhythmia. When SK2 -/- mice or WT were perfused with KHB containing bupivacaine (40 μM), the time to arrhythmia (Tarrhythmia) and time to asystole (Tasystole) were both significantly longer in SK2 -/- mice relative to WT mice (P < 0.001). Similarly, SK2 -/- mice exhibited a significantly longer time to 25%, 50%, and 75% reductions in heart rate (HR) and rate-pressure product (RPP) relative to WT mice following bupivacaine perfusion (P < 0.001). These results reveal that bupivacaine was able to mediate a dose-dependent inhibition of SK2 channels in HEK-293 cells, and deletion of SK2 channels can delay bupivacaine-induced cardiotoxicity in isolated mouse hearts.
Collapse
Affiliation(s)
- H Chen
- Department of Anesthesiology, the 89657First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - F Xia
- Department of Anesthesiology, the 89657First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - X Chen
- Department of Anesthesiology, the 89657First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Y Cai
- Department of Anesthesiology, the 89657First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Z Jin
- Department of Anesthesiology, the 89657First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| |
Collapse
|
9
|
Sun J, Liu Y, Baudry M, Bi X. SK2 channel regulation of neuronal excitability, synaptic transmission, and brain rhythmic activity in health and diseases. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2020; 1867:118834. [PMID: 32860835 PMCID: PMC7541745 DOI: 10.1016/j.bbamcr.2020.118834] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 11/20/2022]
Abstract
Small conductance calcium-activated potassium channels (SKs) are solely activated by intracellular Ca2+ and their activation leads to potassium efflux, thereby repolarizing/hyperpolarizing membrane potential. Thus, these channels play a critical role in synaptic transmission, and consequently in information transmission along the neuronal circuits expressing them. SKs are widely but not homogeneously distributed in the central nervous system (CNS). Activation of SKs requires submicromolar cytoplasmic Ca2+ concentrations, which are reached following either Ca2+ release from intracellular Ca2+ stores or influx through Ca2+ permeable membrane channels. Both Ca2+ sensitivity and synaptic levels of SKs are regulated by protein kinases and phosphatases, and degradation pathways. SKs in turn control the activity of multiple Ca2+ channels. They are therefore critically involved in coordinating diverse Ca2+ signaling pathways and controlling Ca2+ signal amplitude and duration. This review highlights recent advances in our understanding of the regulation of SK2 channels and of their roles in normal brain functions, including synaptic plasticity, learning and memory, and rhythmic activities. It will also discuss how alterations in their expression and regulation might contribute to various brain disorders such as Angelman Syndrome, Alzheimer's disease and Parkinson's disease.
Collapse
Affiliation(s)
- Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Yan Liu
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Michel Baudry
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America.
| |
Collapse
|
10
|
Weisbrod D. Small and Intermediate Calcium Activated Potassium Channels in the Heart: Role and Strategies in the Treatment of Cardiovascular Diseases. Front Physiol 2020; 11:590534. [PMID: 33329039 PMCID: PMC7719780 DOI: 10.3389/fphys.2020.590534] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022] Open
Abstract
Calcium-activated potassium channels are a heterogeneous family of channels that, despite their different biophysical characteristics, structures, and pharmacological signatures, play a role of transducer between the ubiquitous intracellular calcium signaling and the electric variations of the membrane. Although this family of channels was extensively described in various excitable and non-excitable tissues, an increasing amount of evidences shows their functional role in the heart. This review aims to focus on the physiological role and the contribution of the small and intermediate calcium-activated potassium channels in cardiac pathologies.
Collapse
|
11
|
Trombetta-Lima M, Krabbendam IE, Dolga AM. Calcium-activated potassium channels: implications for aging and age-related neurodegeneration. Int J Biochem Cell Biol 2020; 123:105748. [PMID: 32353429 DOI: 10.1016/j.biocel.2020.105748] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/11/2020] [Accepted: 04/14/2020] [Indexed: 12/16/2022]
Abstract
Population aging, as well as the handling of age-associated diseases, is a worldwide increasing concern. Among them, Alzheimer's disease stands out as the major cause of dementia culminating in full dependence on other people for basic functions. However, despite numerous efforts, in the last decades, there was no new approved therapeutic drug for the treatment of the disease. Calcium-activated potassium channels have emerged as a potential tool for neuronal protection by modulating intracellular calcium signaling. Their subcellular localization is determinant of their functional effects. When located on the plasma membrane of neuronal cells, they can modulate synaptic function, while their activation at the inner mitochondrial membrane has a neuroprotective potential via the attenuation of mitochondrial reactive oxygen species in conditions of oxidative stress. Here we review the dual role of these channels in the aging phenotype and Alzheimer's disease pathology and discuss their potential use as a therapeutic tool.
Collapse
Affiliation(s)
- Marina Trombetta-Lima
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands; Medical School, Neurology Department, University of São Paulo (USP), 01246903 São Paulo, Brazil
| | - Inge E Krabbendam
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands
| | - Amalia M Dolga
- Faculty of Science and Engineering, Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy (GRIP), University of Groningen, 9713 AV Groningen, the Netherlands.
| |
Collapse
|
12
|
Balint B, Guerreiro R, Carmona S, Dehghani N, Latorre A, Cordivari C, Bhatia KP, Bras J. KCNN2 mutation in autosomal-dominant tremulous myoclonus-dystonia. Eur J Neurol 2020; 27:1471-1477. [PMID: 32212350 DOI: 10.1111/ene.14228] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/14/2020] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND PURPOSE Despite recent advances in neurogenetics that have facilitated the identification of a number of dystonia genes, many familial dystonia syndromes remain without known cause. The aim of the study was to identify the cause of autosomal dominant tremulous myoclonus-dystonia in a UK kindred with affected individuals in three generations. METHODS Known genetic causes of myoclonus-dystonia were excluded. We combined clinical and electrophysiological phenotyping with whole-exome sequencing and Sanger sequencing to identify candidate causal variants in a family with tremulous myoclonus-dystonia. RESULTS The core phenotype consisted of childhood-onset dystonia predominantly affecting hands and neck, with a fast tremor with superimposed myoclonus and, in some individuals, subtle cerebellar signs. We identified a novel missense variant in potassium calcium-activated channel subfamily N member 2 (KCNN2) [NM_021614:c.1112G>A:p.(Gly371Glu)], which was the only variant that we were able to identify as segregating with the phenotype over three generations. This variant, which is absent from the most recent version of gnomAD, was predicted to be deleterious by SIFT and PolyPhen-2 and had an overall CADD score of 29.7. CONCLUSIONS KCNN2, a member of the KCNN family of potassium channel genes, is highly conserved across species and in humans is highly expressed in the brain, particularly the cerebellum. KCNN2 mutations have never been described as pathological in human disease, but are recognized abnormalities in two rodent models of fast, jerky tremor. Segregation, absence of the variant in the normal population and in-silico prediction of a deleterious effect together with animal models compatible with the clinical phenotype are all in line with KCNN2 mutations being a plausible cause underlying myoclonus-dystonia.
Collapse
Affiliation(s)
- B Balint
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Neurology, University Hospital, Heidelberg, Germany
| | - R Guerreiro
- Dementia Research Institute at UCL and Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK.,Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - S Carmona
- Dementia Research Institute at UCL and Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK.,Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - N Dehghani
- Dementia Research Institute at UCL and Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK.,Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| | - A Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - C Cordivari
- Department of Clinical Neurophysiology, National Hospital for Neurology and Neurosurgery, London, UK
| | - K P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - J Bras
- Dementia Research Institute at UCL and Department of Neurodegenerative Diseases, UCL Institute of Neurology, London, UK.,Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA
| |
Collapse
|
13
|
Hypobaric Hypoxia-Induced Learning and Memory Impairment: Elucidating the Role of Small Conductance Ca2+-Activated K+ Channels. Neuroscience 2018; 388:418-429. [DOI: 10.1016/j.neuroscience.2018.07.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 11/19/2022]
|
14
|
Shaker-related voltage-gated potassium channels Kv1 in human hippocampus. Brain Struct Funct 2018; 223:2663-2671. [PMID: 29564531 DOI: 10.1007/s00429-018-1653-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 03/18/2018] [Indexed: 01/05/2023]
Abstract
In this study, we investigated the tissue expression levels, alpha subunit composition and distribution of Shaker-related voltage-dependent potassium Kv1 channels in human hippocampus by combining western blotting experiments, toxin autoradiography, in vivo radioligand binding studies, immunoprecipitation and immunohistochemistry. Tissue expression of Kv1.1 and Kv1.2 α-subunits in human post-mortem brain tissue was confirmed in immunoblot analysis using a panel of specific monoclonal and polyclonal antibodies. Immunoprecipitation experiments using toxin-prelabeled Kv1 channels revealed that all toxin-sensitive Kv1 channels in human hippocampus contained either a Kv1.1 or Kv1.2 α-subunit with the majority being composed of Kv1.1/Kv1.2 heterotetramers. Receptor autoradiography suggested Kv1.1/Kv1.2 channel expression in the molecular layer of dentate gyrus. In accordance, immunohistochemical experiments also observed Kv1.1 and Kv1.2 α-subunits in the molecular layer of the dentate gyrus, in addition to the CA3 stratum lucidum and the CA1 stratum oriens. These findings indicate expression in axons and terminals of hippocampal pathways, namely the perforant path, the mossy fiber pathway and the Schaffer collaterals. Herein we present the first direct demonstration that Kv1.1 and Kv1.2 channel proteins are targeted to distinct compartments of the human hippocampal formation and that this expression pattern largely reflects their distribution profile in murine brain.
Collapse
|