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Barbaresi P, Fabri M, Lorenzi T, Sagrati A, Morroni M. Intrinsic organization of the corpus callosum. Front Physiol 2024; 15:1393000. [PMID: 39035452 PMCID: PMC11259024 DOI: 10.3389/fphys.2024.1393000] [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: 02/28/2024] [Accepted: 05/16/2024] [Indexed: 07/23/2024] Open
Abstract
The corpus callosum-the largest commissural fiber system connecting the two cerebral hemispheres-is considered essential for bilateral sensory integration and higher cognitive functions. Most studies exploring the corpus callosum have examined either the anatomical, physiological, and neurochemical organization of callosal projections or the functional and/or behavioral aspects of the callosal connections after complete/partial callosotomy or callosal lesion. There are no works that address the intrinsic organization of the corpus callosum. We review the existing information on the activities that take place in the commissure in three sections: I) the topographical and neurochemical organization of the intracallosal fibers, II) the role of glia in the corpus callosum, and III) the role of the intracallosal neurons.
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Affiliation(s)
- Paolo Barbaresi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Mara Fabri
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Teresa Lorenzi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Andrea Sagrati
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Manrico Morroni
- Electron Microscopy Unit, Azienda Ospedaliero-Universitaria, Ancona, Italy
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Flori L, Spezzini J, Calderone V, Testai L. Role of mitochondrial potassium channels in ageing. Mitochondrion 2024; 76:101857. [PMID: 38403095 DOI: 10.1016/j.mito.2024.101857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/13/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Ageing is described as an inevitable decline in body functions over time and an increase in susceptibility to age-related diseases. Therefore, the increase of life expectancy is also viewed as a condition in which many elderly will develop age-related diseases and disabilities, such as cardiovascular, metabolic, neurological and oncological ones. Currently, several recognized cellular hallmarks of senescence are taken in consideration to evaluate the level of biological ageing and are the topic to plan preventive/curative anti-ageing interventions, including genomic instability, epigenetic alterations, and mitochondrial dysfunction. In this scenario, alterations in the function/expression of mitochondrial ion channels have been found in ageing and associated to an impairment of calcium cycling and a reduced mitochondrial membrane potential. Although several ion channels have been described at mitochondrial level, undoubtedly the mitochondrial potassium (mitoK) channels are the most investigated. Therefore, this review summarized the evidence that sheds to light a correlation between age-related diseases and alteration of mitoK channels, focusing the attention of the main age-related diseases, i.e. cardiovascular, neurological and oncological ones.
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Affiliation(s)
- Lorenzo Flori
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | | | - Vincenzo Calderone
- Department of Pharmacy, University of Pisa, Pisa, Italy; Interdepartmental Research Centre of Ageing Biology and Pathology, University of Pisa, Pisa, Italy
| | - Lara Testai
- Department of Pharmacy, University of Pisa, Pisa, Italy; Interdepartmental Research Centre of Ageing Biology and Pathology, University of Pisa, Pisa, Italy.
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Abd El-Rahman AA, El-Shafei SMA, Shehab GMG, Mansour L, Abuelsaad ASA, Gad RA. Assessment of Biochemical and Neuroactivities of Cultural Filtrate from Trichoderma harzianum in Adjusting Electrolytes and Neurotransmitters in Hippocampus of Epileptic Rats. Life (Basel) 2023; 13:1815. [PMID: 37763219 PMCID: PMC10533195 DOI: 10.3390/life13091815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 07/29/2023] [Accepted: 08/15/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Epilepsy is a serious chronic neurological disorder, which is accompanied by recurrent seizures. Repeated seizures cause physical injuries and neuronal dysfunction and may be a risk of cancer and vascular diseases. However, many antiepileptic drugs (AEDs) have side effects of mood alteration or neurocognitive function, a reduction in neuron excitation, and the inhibition of normal activity. Therefore, the present study aimed to evaluate the effect of secondary metabolites of Trichoderma harzianum cultural filtrate (ThCF) when adjusting different electrolytes and neurotransmitters in the hippocampus of epileptic rats. METHODS Cytotoxicity of ThCF against LS-174T cancer cells was assessed using a sulforhodamine B (SRB) assay. Quantitative estimation for some neurotransmitters, electrolytes in sera or homogenate of hippocampi tissues, and mRNA gene expression for ion or voltage gates was assessed by quantitative Real-Time PCR. RESULTS Treatment with ThCF reduces the proliferative percentage of LS-174T cells in a concentration-dependent manner. ThCF administration improves hyponatremia, hyperkalemia, and hypocalcemia in the sera of the epilepticus model. ThCF rebalances the elevated levels of many neurotransmitters and reduces the release of GABA and acetylcholine-esterase. Also, treatments with ThCF ameliorate the downregulation of mRNA gene expression for some gate receptors in hippocampal homogenate tissues and recorded a highly significant elevation in the expression of SCN1A, CACNA1S, and NMDA. CONCLUSION Secondary metabolites of Trichoderma (ThCF) have cytotoxic activity against LS-174T (colorectal cancer cell line) and anxiolytic-like activity through a GABAergic mechanism of action and an increase in GABA as inhibitory amino acid in the selected brain regions and reduced levels of NMDA and DOPA. The present data suggested that ThCF may inhibit intracellular calcium accumulation by triggering the NAADP-mediated Ca2+ signaling pathway. Therefore, the present results suggested further studies on the molecular pathway for each metabolite of ThCF, e.g., 6-pentyl-α-pyrone (6-PP), harzianic acid (HA), and hydrophobin, as an alternative drug to mitigate the side effects of AEDs.
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Affiliation(s)
- Atef A. Abd El-Rahman
- Department of Agricultural Chemistry, Faculty of Agriculture, Minia University, El-Minya 61519, Egypt;
| | - Sally M. A. El-Shafei
- Department of Agricultural Chemistry, Faculty of Agriculture, Minia University, El-Minya 61519, Egypt;
| | - Gaber M. G. Shehab
- Department of Biochemistry, Faculty of Agriculture, Cairo University, Giza 12613, Egypt;
| | - Lamjed Mansour
- Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Abdelaziz S. A. Abuelsaad
- Immunology Division, Zoology Department, Faculty of Science, Beni-Suef University, Beni-Suef 62521, Egypt;
| | - Rania A. Gad
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, NAHDA University (NUB), Beni-Suef 62511, Egypt;
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Nageeb Hasan SM, Clarke CL, McManamon Strand TP, Bambico FR. Putative pathological mechanisms of late-life depression and Alzheimer's Disease. Brain Res 2023:148423. [PMID: 37244602 DOI: 10.1016/j.brainres.2023.148423] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by progressive impairment in cognition and memory. AD is accompanied by several neuropsychiatric symptoms, with depression being the most prominent. Although depression has long been known to be associated with AD, controversial findings from preclinical and clinical studies have obscured the precise nature of this association. However recent evidence suggests that depression could be a prodrome or harbinger of AD. Evidence indicates that the major central serotonergic nucleus-the dorsal raphe nucleus (DRN)-shows very early AD pathology: neurofibrillary tangles made of hyperphosphorylated tau protein and degenerated neurites. AD and depression share common pathophysiologies, including functional deficits of the serotonin (5-HT) system. 5-HT receptors have modulatory effects on the progression of AD pathology i.e., reduction in Aβ load, increased hyper-phosphorylation of tau, decreased oxidative stress etc. Moreover, preclinical models show a role for specific channelopathies that result in abnormal regional activational and neuroplasticity patterns. One of these concerns the pathological upregulation of the small conductance calcium-activated potassium (SK) channel in corticolimbic structure. This has also been observed in the DRN in both diseases. The SKC is a key regulator of cell excitability and long-term potentiation (LTP). SKC over-expression is positively correlated with aging and cognitive decline, and is evident in AD. Pharmacological blockade of SKCs has been reported to reverse symptoms of depression and AD. Thus, aberrant SKC functioning could be related to depression pathophysiology and diverts its late-life progression towards the development of AD. We summarize findings from preclinical and clinical studies suggesting a molecular linkage between depression and AD pathology. We also provide a rationale for considering SKCs as a novel pharmacological target for the treatment of AD-associated symptoms.
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Affiliation(s)
- S M Nageeb Hasan
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada.
| | - Courtney Leigh Clarke
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada
| | | | - Francis Rodriguez Bambico
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada; Behavioural Neurobiology Laboratory, Centre for Addiction and Mental Health, Toronto, ON, M5T1R8, Canada
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Xu S, Yi Y, Wang Y, Wang P, Zhao Y, Feng W. Dexmedetomidine Alleviates Neuropathic Pain via the TRPC6-p38 MAPK Pathway in the Dorsal Root Ganglia of Rats. J Pain Res 2022; 15:2437-2448. [PMID: 36016537 PMCID: PMC9397435 DOI: 10.2147/jpr.s378893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/15/2022] [Indexed: 12/02/2022] Open
Abstract
Purpose Neuropathic pain is a chronic intractable disease characterized by allodynia and hyperalgesia. Effective treatments are unavailable because of the complicated mechanisms of neuropathic pain. Transient receptor potential canonical 6 (TRPC6) is a nonselective calcium (Ca2+)-channel protein related to hyperalgesia. Dexmedetomidine (Dex) is an alpha-2 (α2) adrenoreceptor agonist that mediates intracellular Ca2+ levels to alleviate pain. However, the relationship between TRPC6 and Dex is currently unclear. We speculated that the α2 receptor agonist would be closely linked to the TRPC6 channel. We aimed to investigate whether Dex relieves neuropathic pain by the TRPC6 pathway in the dorsal root ganglia (DRG). Methods The chronic constriction injury (CCI) model was established in male rats, and we evaluated the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). The expression of TRPC6 and Iba-1 in the DRG were analyzed using quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence assay. The levels of inflammatory cytokines were measured using an enzyme-linked immunosorbent assay. Results Compared with the CCI normal saline group, both the MWT and TWL were significantly improved after 7 days of Dex administration. Results demonstrated that TRPC6 expression was increased in the DRG following CCI but was suppressed by Dex. In addition, multiple administrations of Dex inhibited the phosphorylation level of p38 mitogen-activated protein kinase and the upregulation of neuroinflammatory factors. Conclusion The results of this study demonstrated that Dex exhibits anti-nociceptive and anti-inflammatory properties in a neuropathic pain model. Moreover, our findings of the CCI model suggested that Dex has an inhibitory effect on TRPC6 expression in the DRG by decreasing the phosphorylation level of p38 in the DRG.
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Affiliation(s)
- Songchao Xu
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, People’s Republic of China
| | - Yusheng Yi
- Department of Algology, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, People’s Republic of China
| | - Yanting Wang
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, People’s Republic of China
| | - Pei Wang
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, People’s Republic of China
| | - Yang Zhao
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, People’s Republic of China
| | - Wei Feng
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, People’s Republic of China
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Matschke LA, Komadowski MA, Stöhr A, Lee B, Henrich MT, Griesbach M, Rinné S, Geibl FF, Chiu WH, Koprich JB, Brotchie JM, Kiper AK, Dolga AM, Oertel WH, Decher N. Enhanced firing of locus coeruleus neurons and SK channel dysfunction are conserved in distinct models of prodromal Parkinson's disease. Sci Rep 2022; 12:3180. [PMID: 35210472 PMCID: PMC8873463 DOI: 10.1038/s41598-022-06832-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/07/2022] [Indexed: 12/21/2022] Open
Abstract
Parkinson's disease (PD) is clinically defined by the presence of the cardinal motor symptoms, which are associated with a loss of dopaminergic nigrostriatal neurons in the substantia nigra pars compacta (SNpc). While SNpc neurons serve as the prototypical cell-type to study cellular vulnerability in PD, there is an unmet need to extent our efforts to other neurons at risk. The noradrenergic locus coeruleus (LC) represents one of the first brain structures affected in Parkinson's disease (PD) and plays not only a crucial role for the evolving non-motor symptomatology, but it is also believed to contribute to disease progression by efferent noradrenergic deficiency. Therefore, we sought to characterize the electrophysiological properties of LC neurons in two distinct PD models: (1) in an in vivo mouse model of focal α-synuclein overexpression; and (2) in an in vitro rotenone-induced PD model. Despite the fundamental differences of these two PD models, α-synuclein overexpression as well as rotenone exposure led to an accelerated autonomous pacemaker frequency of LC neurons, accompanied by severe alterations of the afterhyperpolarization amplitude. On the mechanistic side, we suggest that Ca2+-activated K+ (SK) channels are mediators of the increased LC neuronal excitability, as pharmacological activation of these channels is sufficient to prevent increased LC pacemaking and subsequent neuronal loss in the LC following in vitro rotenone exposure. These findings suggest a role of SK channels in PD by linking α-synuclein- and rotenone-induced changes in LC firing rate to SK channel dysfunction.
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Affiliation(s)
- Lina A Matschke
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany.,Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Marlene A Komadowski
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Annette Stöhr
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Bolam Lee
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Martin T Henrich
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Markus Griesbach
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Susanne Rinné
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Fanni F Geibl
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - Wei-Hua Chiu
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany
| | - James B Koprich
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 8KD402, Toronto, ON, M5T 2S8, Canada
| | - Jonathan M Brotchie
- Krembil Research Institute, Toronto Western Hospital, University Health Network, 8KD402, Toronto, ON, M5T 2S8, Canada
| | - Aytug K Kiper
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany
| | - Amalia M Dolga
- Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Department of Molecular Pharmacology, University of Groningen, 9713 AV, Groningen, The Netherlands
| | - Wolfgang H Oertel
- Clinic for Neurology, Philipps-University Marburg, 35043, Marburg, Germany.,Hertie Senior Research Professor of the Charitable Hertie Foundation, 60323, Frankfurt am Main, Germany
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology and Marburg Center for Mind, Brain and Behavior - MCMBB, Philipps-University Marburg, 35037, Marburg, Germany.
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7
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Luján R, Merchán-Pérez A, Soriano J, Martín-Belmonte A, Aguado C, Alfaro-Ruiz R, Moreno-Martínez AE, DeFelipe J. Neuron Class and Target Variability in the Three-Dimensional Localization of SK2 Channels in Hippocampal Neurons as Detected by Immunogold FIB-SEM. Front Neuroanat 2022; 15:781314. [PMID: 34975419 PMCID: PMC8715088 DOI: 10.3389/fnana.2021.781314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/19/2021] [Indexed: 11/22/2022] Open
Abstract
Small-conductance calcium-activated potassium (SK) channels are crucial for learning and memory. However, many aspects of their spatial organization in neurons are still unknown. In this study, we have taken a novel approach to answering these questions combining a pre-embedding immunogold labeling with an automated dual-beam electron microscope that integrates focused ion beam milling and scanning electron microscopy (FIB/SEM) to gather 3D map ultrastructural and biomolecular information simultaneously. Using this new approach, we evaluated the number and variability in the density of extrasynaptic SK2 channels in 3D reconstructions from six dendritic segments of excitatory neurons and six inhibitory neurons present in the stratum radiatum of the CA1 region of the mouse. SK2 immunoparticles were observed throughout the surface of hippocampal neurons, either scattered or clustered, as well as at intracellular sites. Quantitative volumetric evaluations revealed that the extrasynaptic SK2 channel density in spines was seven times higher than in dendritic shafts and thirty-five times higher than in interneurons. Spines showed a heterogeneous population of SK2 expression, some spines having a high SK2 content, others having a low content and others lacking SK2 channels. SK2 immunonegative spines were significantly smaller than those immunopositive. These results show that SK2 channel density differs between excitatory and inhibitory neurons and demonstrates a large variability in the density of SK2 channels in spines. Furthermore, we demonstrated that SK2 expression was associated with excitatory synapses, but not with inhibitory synapses in CA1 pyramidal cells. Consequently, regulation of excitability and synaptic plasticity by SK2 channels is expected to be neuron class- and target-specific. These data show that immunogold FIB/SEM represent a new powerful EM tool to correlate structure and function of ion channels with nanoscale resolution.
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Affiliation(s)
- Rafael Luján
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha, Albacete, Spain
| | - Angel Merchán-Pérez
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid, Spain
| | - Joaquim Soriano
- CRIB-Facultad de Medicina, Universidad Castilla-La Mancha, Albacete, Spain
| | - Alejandro Martín-Belmonte
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha, Albacete, Spain
| | - Carolina Aguado
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha, Albacete, Spain
| | - Rocío Alfaro-Ruiz
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha, Albacete, Spain
| | - Ana Esther Moreno-Martínez
- Synaptic Structure Laboratory, Instituto de Investigación en Discapacidades Neurológicas (IDINE), Departamento de Ciencias Médicas, Facultad de Medicina, Universidad Castilla-La Mancha, Albacete, Spain
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, Madrid, Spain.,Instituto Cajal (CSIC), Madrid, Spain
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Bredehöft J, Dolga AM, Honrath B, Wache S, Mazurek S, Culmsee C, Schoemaker RG, Gerstberger R, Roth J, Rummel C. SK-Channel Activation Alters Peripheral Metabolic Pathways in Mice, but Not Lipopolysaccharide-Induced Fever or Inflammation. J Inflamm Res 2022; 15:509-531. [PMID: 35115803 PMCID: PMC8800008 DOI: 10.2147/jir.s338812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/25/2021] [Indexed: 12/19/2022] Open
Abstract
Purpose Previously, we have shown that CyPPA (cyclohexyl-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-pyrimidin-4-yl]-amine), a pharmacological small-conductance calcium-activated potassium (SK)–channel positive modulator, antagonizes lipopolysaccharide (LPS)-induced cytokine expression in microglial cells. Here, we aimed to test its therapeutic potential for brain-controlled sickness symptoms, brain inflammatory response during LPS-induced systemic inflammation, and peripheral metabolic pathways in mice. Methods Mice were pretreated with CyPPA (15 mg/kg IP) 24 hours before and simultaneously with LPS stimulation (2.5 mg/kg IP), and the sickness response was recorded by a telemetric system for 24 hours. A second cohort of mice were euthanized 2 hours after CyPPA or solvent treatment to assess underlying CyPPA-induced mechanisms. Brain, blood, and liver samples were analyzed for inflammatory mediators or nucleotide concentrations using immunohistochemistry, real-time PCR and Western blot, or HPLC. Moreover, we investigated CyPPA-induced changes of UCP1 expression in brown adipose tissue (BAT)–explant cultures. Results CyPPA treatment did not affect LPS-induced fever, anorexia, adipsia, or expression profiles of inflammatory mediators in the hypothalamus or plasma or microglial reactivity to LPS (CD11b staining and CD68 mRNA expression). However, CyPPA alone induced a rise in core body temperature linked to heat production via altered metabolic pathways like reduced levels of adenosine, increased protein content, and increased UCP1 expression in BAT-explant cultures, but no alteration in ATP/ADP concentrations in the liver. CyPPA treatment was accompanied by altered pathways, including NFκB signaling, in the hypothalamus and cortex, while circulating cytokines remained unaltered. Conclusion Overall, while CyPPA has promise as a treatment strategy, in particular according to results from in vitro experiments, we did not reveal anti-inflammatory effects during severe LPS-induced systemic inflammation. Interestingly, we found that CyPPA alters metabolic pathways inducing short hyperthermia, most likely due to increased energy turnover in the liver and heat production in BAT.
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Affiliation(s)
- Janne Bredehöft
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Giessen, Germany
| | - Amalia M Dolga
- Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
| | - Birgit Honrath
- Department of Molecular Pharmacology, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
- Institute of Pharmacology and Clinical Pharmacy, Philipps University of Marburg, Marburg, Germany
| | - Sybille Wache
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Giessen, Germany
| | - Sybille Mazurek
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Giessen, Germany
| | - Carsten Culmsee
- Institute of Pharmacology and Clinical Pharmacy, Philipps University of Marburg, Marburg, Germany
- Center for Mind, Brain and Behavior-CMBB, Giessen and Marburg, Germany
| | - Regien G Schoemaker
- Department of Neurobiology, GELIFES, University of Groningen, Groningen, Netherlands
| | - Rüdiger Gerstberger
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Giessen, Germany
| | - Joachim Roth
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Giessen, Germany
- Center for Mind, Brain and Behavior-CMBB, Giessen and Marburg, Germany
| | - Christoph Rummel
- Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Giessen, Germany
- Center for Mind, Brain and Behavior-CMBB, Giessen and Marburg, Germany
- Correspondence: Christoph Rummel Institute of Veterinary Physiology and Biochemistry, Justus Liebig University Giessen, Frankfurter Strasse 100, GiessenD-35392, GermanyTel +49 641 99 38155Fax +49 641 99 38159 Email
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Abd El-Hameed AM, Abuelsaad ASA, Khalil A. Bee venom acupuncture therapy ameliorates neuroinflammatory alterations in a pilocarpine-induced epilepticus model. Metab Brain Dis 2021; 36:2047-2058. [PMID: 34138441 DOI: 10.1007/s11011-021-00766-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 06/06/2021] [Indexed: 11/25/2022]
Abstract
Bee venom (BV) is applied in different traditional medicinal therapies and is used worldwide to prevent and treat many acute and chronic diseases. Epilepsy has various neurological effects, e.g., epileptogenic insults; thus, it is considered a life-threatening condition. Seizures and their effects add to the burden of epilepsy because they can have health effects including residual disability and even premature mortality. The use of antiinflammatory drugs to treat epilepsy is controversial; therefore, the alternative nonchemical apitherapy benefits of BV were evaluated in the present study by assessing neuroinflammatory changes in a pilocarpine-induced epilepticus model. Levels of electrolytes, neurotransmitters, and mRNA expression for some gate channels were determined. Moreover, ELISA assays were conducted to detect pro- and anti-inflammatory cytokines, whereas RT-PCR was performed to assess mRNA expression of Foxp3 and CTLA-4. BV ameliorated the interruption in electrolytes and ions through voltage- and ligand-gated ion channels, and it limited neuronal excitability via rapid repolarization of action potentials. In addition, BV inhibited the high expression of proinflammatory cytokines. Acupuncture with BV was effective in preventing some of the deleterious consequences of epileptogenesis associated with high levels of glutamate and DOPA in the hippocampus. BV ameliorates changes in the expression of voltage-gated channels, rebalances blood electrolytes and neurotransmitters, and modulates the levels of pro- and anti-inflammatory cytokines. Thus, BV could reduce the progression of epileptogenesis as a cotherapy with other antiepileptic drugs.
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Affiliation(s)
| | - Abdelaziz S A Abuelsaad
- Immunology Division, Department of Zoology, Faculty of Science, Beni-Suef University, 62511, Beni-Suef, Egypt.
| | - Abdelwahab Khalil
- Medical Entomology Division, Department of Zoology, Faculty of Science, Beni-Suef University, Beni-Suef, 62521, Egypt
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Ehinger R, Kuret A, Matt L, Frank N, Wild K, Kabagema-Bilan C, Bischof H, Malli R, Ruth P, Bausch AE, Lukowski R. Slack K + channels attenuate NMDA-induced excitotoxic brain damage and neuronal cell death. FASEB J 2021; 35:e21568. [PMID: 33817875 DOI: 10.1096/fj.202002308rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/14/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022]
Abstract
The neuronal Na+ -activated K+ channel Slack (aka Slo2.2, KNa 1.1, or Kcnt1) has been implicated in setting and maintaining the resting membrane potential and defining excitability and firing patterns, as well as in the generation of the slow afterhyperpolarization following bursts of action potentials. Slack activity increases significantly under conditions of high intracellular Na+ levels, suggesting this channel may exert important pathophysiological functions. To address these putative roles, we studied whether Slack K+ channels contribute to pathological changes and excitotoxic cell death caused by glutamatergic overstimulation of Ca2+ - and Na+ -permeable N-methyl-D-aspartic acid receptors (NMDAR). Slack-deficient (Slack KO) and wild-type (WT) mice were subjected to intrastriatal microinjections of the NMDAR agonist NMDA. NMDA-induced brain lesions were significantly increased in Slack KO vs WT mice, suggesting that the lack of Slack renders neurons particularly susceptible to excitotoxicity. Accordingly, excessive neuronal cell death was seen in Slack-deficient primary cerebellar granule cell (CGC) cultures exposed to glutamate and NMDA. Differences in neuronal survival between WT and Slack KO CGCs were largely abolished by the NMDAR antagonist MK-801, but not by NBQX, a potent and highly selective competitive antagonist of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type ionotropic glutamate receptors. Interestingly, NMDAR-evoked Ca2+ signals did not differ with regard to Slack genotype in CGCs. However, real-time monitoring of K+ following NMDAR activation revealed a significant contribution of this channel to the intracellular drop in K+ . Finally, TrkB and TrkC neurotrophin receptor transcript levels were elevated in NMDA-exposed Slack-proficient CGCs, suggesting a mechanism by which this K+ channel contributes to the activation of the extracellular-signal-regulated kinase (Erk) pathway and thereby to neuroprotection. Combined, our findings suggest that Slack-dependent K+ signals oppose the NMDAR-mediated excitotoxic neuronal injury by promoting pro-survival signaling via the BDNF/TrkB and Erk axis.
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Affiliation(s)
- Rebekka Ehinger
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Anna Kuret
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Lucas Matt
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Nadine Frank
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Katharina Wild
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Clement Kabagema-Bilan
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Helmut Bischof
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Peter Ruth
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Anne E Bausch
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Tübingen, Germany
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11
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Luo L, Song S, Ezenwukwa CC, Jalali S, Sun B, Sun D. Ion channels and transporters in microglial function in physiology and brain diseases. Neurochem Int 2020; 142:104925. [PMID: 33248207 DOI: 10.1016/j.neuint.2020.104925] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/19/2022]
Abstract
Microglial cells interact with all components of the central nervous system (CNS) and are increasingly recognized to play essential roles during brain development, homeostasis and disease pathologies. Functions of microglia include maintaining tissue integrity, clearing cellular debris and dead neurons through the process of phagocytosis, and providing tissue repair by releasing anti-inflammatory cytokines and neurotrophic factors. Changes of microglial ionic homeostasis (Na+, Ca2+, K+, H+, Cl-) are important for microglial activation, including proliferation, migration, cytokine release and reactive oxygen species production, etc. These are mediated by ion channels and ion transporters in microglial cells. Here, we review the current knowledge about the role of major microglial ion channels and transporters, including several types of Ca2+ channels (store-operated Ca2+ entry (SOCE) channels, transient receptor potential (TRP) channels and voltage-gated Ca2+ channels (VGCCs)) and Na+ channels (voltage-gated Na+ channels (Nav) and acid-sensing ion channels (ASICs)), K+ channels (inward rectifier K+ channels (Kir), voltage-gated K+ channels (KV) and calcium-activated K+ channels (KCa)), proton channels (voltage-gated proton channel (Hv1)), and Cl- channels (volume (or swelling)-regulated Cl- channels (VRCCs) and chloride intracellular channels (CLICs)). In addition, ion transporter proteins such as Na+/Ca2+ exchanger (NCX), Na+-K+-Cl- cotransporter (NKCC1), and Na+/H+ exchanger (NHE1) are also involved in microglial function in physiology and brain diseases. We discussed microglial activation and neuroinflammation in relation to the ion channel/transporter stimulation under brain disease conditions and therapeutic aspects of targeting microglial ion channels/transporters for neurodegenerative disease, ischemic stroke, traumatic brain injury and neuropathic pain.
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Affiliation(s)
- Lanxin Luo
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China; Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | | | - Shayan Jalali
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Baoshan Sun
- Pólo DoisPortos, Instituto National de InvestigaçãoAgrária e Veterinária, I.P., Quinta da Almoinha, DoisPortos, 2565-191, Portugal.
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, PA, 15213, USA.
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12
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Transcript Profiles of Stria Vascularis in Models of Waardenburg Syndrome. Neural Plast 2020; 2020:2908182. [PMID: 32802035 PMCID: PMC7416267 DOI: 10.1155/2020/2908182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/18/2020] [Accepted: 06/26/2020] [Indexed: 12/13/2022] Open
Abstract
Background Waardenburg syndrome is an uncommon genetic condition characterized by at least some degree of congenital hearing loss and pigmentation deficiencies. However, the genetic pathway affecting the development of stria vascularis is not fully illustrated. Methods The transcript profile of stria vascularis of Waardenburg syndrome was studied using Mitf-M mutant pig and mice models. Therefore, GO analysis was performed to identify the differential gene expression caused by Mitf-M mutation. Results There were 113 genes in tyrosine metabolism, melanin formation, and ion transportations showed significant changes in pig models and 191 genes in mice models. In addition, there were some spice's specific gene changes in the stria vascularis in the mouse and porcine models. The expression of tight junction-associated genes, including Cadm1, Cldn11, Pcdh1, Pcdh19, and Cdh24 genes, were significantly higher in porcine models compared to mouse models. Vascular-related and ion channel-related genes in the stria vascularis were also shown significantly difference between the two species. The expression of Col2a1, Col3a1, Col11a1, and Col11a2 genes were higher, and the expression of Col8a2, Cd34, and Ncam genes were lower in the porcine models compared to mouse models. Conclusions Our data suggests that there is a significant difference on the gene expression and function between these two models.
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13
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Apamin Suppresses LPS-Induced Neuroinflammatory Responses by Regulating SK Channels and TLR4-Mediated Signaling Pathways. Int J Mol Sci 2020; 21:ijms21124319. [PMID: 32560481 PMCID: PMC7352249 DOI: 10.3390/ijms21124319] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/11/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023] Open
Abstract
Neuroinflammation plays a vital role in neurodegenerative conditions. Microglia are a key component of the neuroinflammatory response. There is a growing interest in developing drugs to target microglia and thereby control neuroinflammatory processes. Apamin (APM) is a specifically selective antagonist of small conductance calcium-activated potassium (SK) channels. However, its effect on neuroinflammation is largely unknown. We examine the effects of APM on lipopolysaccharide (LPS)-stimulated BV2 and rat primary microglial cells. Regarding the molecular mechanism by which APM significantly inhibits proinflammatory cytokine production and microglial cell activation, we found that APM does so by reducing the expression of phosphorylated CaMKII and toll-like receptor (TLR4). In particular, APM potently suppressed the translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/signal transducer and activator of transcription (STAT)3 and phosphorylated mitogen-activated protein kinases (MAPK)-extracellular signal-regulated kinase (ERK). In addition, the correlation of NF-κB/STAT3 and MAPK-ERK in the neuroinflammatory response was verified through inhibitors. The literature and our findings suggest that APM is a promising candidate for an anti-neuroinflammatory agent and can potentially be used for the prevention and treatment of various neurological disorders.
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14
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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.
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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.
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15
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Mi Z, Yang J, He Q, Zhang X, Xiao Y, Shu Y. Alterations of Electrophysiological Properties and Ion Channel Expression in Prefrontal Cortex of a Mouse Model of Schizophrenia. Front Cell Neurosci 2019; 13:554. [PMID: 31920555 PMCID: PMC6927988 DOI: 10.3389/fncel.2019.00554] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/02/2019] [Indexed: 11/13/2022] Open
Abstract
Maternal immune activation (MIA) and juvenile social isolation (SI) are two most prevalent and widely accepted environmental insults that could increase the propensity of psychiatric illnesses. Using a two-hit mouse model, we examined the impact of the combination of these two factors on animal behaviors, neuronal excitability and expressions of voltage-gated sodium (Nav) and small conductance calcium-activated potassium (SK) channels in the prefrontal cortex (PFC). We found that MIA-SI induced a number of schizophrenia-related behavioral deficits. Patch clamp recordings revealed alterations in electrophysiological properties of PFC layer-5 pyramidal cells, including hyperpolarized resting membrane potential (RMP), increased input resistance and enhanced medium after-hyperpolarization (mAHP). MIA-SI also increased the ratio of the maximal slope of somatodendritic potential to the peak slope of action potential upstroke, indicating a change in perisomatic Nav availability. Consistently, MIA-SI significantly increased the expression level of Nav1.2 and SK3 channels that contribute to the somatodendritic potential and the mAHP, respectively. Together, these changes may alter neuronal signaling in the PFC and behavioral states, representing a molecular imprint of environmental insults associated with neuropsychiatric illnesses.
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Affiliation(s)
- Zhen Mi
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Jun Yang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Quansheng He
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Xiaowen Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Yujie Xiao
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Yousheng Shu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.,IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
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16
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Villa C, Suphesiz H, Combi R, Akyuz E. Potassium channels in the neuronal homeostasis and neurodegenerative pathways underlying Alzheimer's disease: An update. Mech Ageing Dev 2019; 185:111197. [PMID: 31862274 DOI: 10.1016/j.mad.2019.111197] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/27/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023]
Abstract
With more than 80 subunits, potassium (K+) channels represent a group of ion channels showing high degree of diversity and ubiquity. They play important role in the control of membrane depolarization and cell excitability in several tissues, including the brain. Controlling the intracellular and extracellular K+ flow in cells, they also modulate the hormone and neurotransmitter release, apoptosis and cell proliferation. It is therefore not surprising that an improper functioning of K+ channels in neurons has been associated with pathophysiology of a wide range of neurological disorders, especially Alzheimer's disease (AD). This review aims to give a comprehensive overview of the basic properties and pathophysiological functions of the main classes of K+ channels in the context of disease processes, also discussing the progress, challenges and opportunities to develop drugs targeting these channels as potential pharmacological approach for AD treatment.
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Affiliation(s)
- Chiara Villa
- School of Medicine and Surgery, University of Milano-Bicocca, Italy
| | | | - Romina Combi
- School of Medicine and Surgery, University of Milano-Bicocca, Italy
| | - Enes Akyuz
- Yozgat Bozok University, Medical Faculty, Department of Biophysics, Yozgat, Turkey.
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17
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Chen T, Zhu J, Hang CH, Wang YH. The Potassium SK Channel Activator NS309 Protects Against Experimental Traumatic Brain Injury Through Anti-Inflammatory and Immunomodulatory Mechanisms. Front Pharmacol 2019; 10:1432. [PMID: 31849677 PMCID: PMC6895208 DOI: 10.3389/fphar.2019.01432] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 11/08/2019] [Indexed: 12/22/2022] Open
Abstract
Neuroinflammation plays important roles in neuronal cell death and functional deficits after TBI. Small conductance Ca2+-activated K+ channels (SK) have been shown to be potential therapeutic targets for treatment of neurological disorders, such as stroke and Parkinson’s disease (PD). The aim of the present study was to investigate the role of SK channels in an animal model of TBI induced by controlled cortical impact (CCI). The SK channels activator NS309 at a concentration of 2 mg/kg was administered by intraperitoneal injection, and no obviously organ-related toxicity of NS309 was found in Sprague-Dawley (SD) rats. Treatment with NS309 significantly reduced brain edema after TBI, but had no effect on contusion volume. This protection can be observed even when the administration was delayed by 4 h after injury. NS309 attenuated the TBI-induced deficits in neurological function, which was accompanied by the reduced neuronal apoptosis. The results of immunohistochemistry showed that NS309 decreased the number of neutrophils, lymphocytes, and microglia cells, with no effect on astrocytes. In addition, NS309 markedly decreased the levels of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and chemokines (MCP-1, MIP-2, and RANTES), but increased the levels of anti-inflammatory cytokines (IL-4, IL-10, and TGF-β1) after TBI. The results of RT-PCR and western blot showed that NS309 increased TSG-6 expression and inhibited NF-κB activation. Furthermore, knockdown of TSG-6 using in vivo transfection with TSG-6 specific shRNA partially reversed the protective and anti-inflammatory effects of NS309 against TBI. In summary, our results indicate that the SK channel activator NS309 could modulate inflammation-associated immune cells and cytokines via regulating the TSG-6/NF-κB pathway after TBI. The present study offers a new sight into the mechanisms responsible for SK channels activation with implications for the treatment of TBI.
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Affiliation(s)
- Tao Chen
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China.,Department of Neurosurgery, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jie Zhu
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
| | - Chun-Hua Hang
- Department of Neurosurgery, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yu-Hai Wang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
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18
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Al Dera H, Alassiri M, Eleawa SM, AlKhateeb MA, Hussein AM, Dallak M, Sakr HF, Alqahtani S, Khalil MA. Melatonin Improves Memory Deficits in Rats with Cerebral Hypoperfusion, Possibly, Through Decreasing the Expression of Small-Conductance Ca 2+-Activated K + Channels. Neurochem Res 2019; 44:1851-1868. [PMID: 31187398 DOI: 10.1007/s11064-019-02820-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 05/02/2019] [Accepted: 05/27/2019] [Indexed: 12/18/2022]
Abstract
This study investigated the expression pattern, regulation of expression, and the role of hippocampal small-conductance Ca2+-activated K+ (SK) channels in memory deficits after cerebral hypoperfusion (CHP) with or without melatonin treatment, in rats. Adults male Wistar rats (n = 20/group) were divided into (1) a sham (2) a sham + melatonin (3) a two-vessel occlusion (2-VO) model, and (4) a 2-VO + melatonin. Melatonin was administered (i.p.) to all rats at a daily dose of 10 mg kg-1 for 7 days starting at the time of 2-VO-induction. In contrast to 2-VO rats, melatonin increased the latency of the passive avoidance learning test and decreased time to find the hidden platform in Water Morris Test in all tested rats. In addition, it concomitantly downregulated SK1, SK2, and SK3 channels, downregulated mRNA levels of TNFα and IL-1β, enhanced BDNF levels and activity of PKA levels, and restored the levels of cholinergic markers in the hippocampi of the treated-rats. Mechanistically, melatonin significantly prevented CHP-induced activation of ERK1/2, JNK, and P38 MAPK at least by inhibiting ROS generation and enhancing the total antioxidant potential. In cultured hypoxic hippocampal neurons, individual blockage of MAPK signaling by the MEK1/2 inhibitor (U0126), but not by the P38 inhibitor (SB203580) or JNK inhibitor (SP600125), completely prevented the upregulation of all three kinds of SK channels. These data clearly confirm that upregulation of SK channels plays a role in CHP-induced memory loss and indicate that melatonin reverses memory deficits after CHP in rats, at least by, downregulation of SK1, SK2, and SK3 channels in their hippocampi.
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Affiliation(s)
- Hussain Al Dera
- Department of Basic Medical Sciences, College of Medicine At King Saud, Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Kingdom of Saudi Arabia. .,King Abdullah International Medical Research Center (KAIMRC), Riyadh, Kingdom of Saudi Arabia.
| | - Mohammed Alassiri
- Department of Basic Medical Sciences, College of Medicine At King Saud, Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Kingdom of Saudi Arabia.,King Abdullah International Medical Research Center (KAIMRC), Riyadh, Kingdom of Saudi Arabia
| | - Samy M Eleawa
- Department of Applied Medical Sciences, College of Health Sciences, Dept., PAAET, Adailiyah, Kuwait
| | - Mahmoud A AlKhateeb
- Department of Basic Medical Sciences, College of Medicine At King Saud, Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Kingdom of Saudi Arabia
| | - Abdelaziz M Hussein
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Mohammad Dallak
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Hussein F Sakr
- Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.,Department of Medical Physiology, College of Medicine, King Khalid University, Abha, Kingdom of Saudi Arabia
| | - Sultan Alqahtani
- Department of Basic Medical Sciences, College of Medicine At King Saud, Abdulaziz University for Health Sciences (KSAU-HS), Riyadh, Kingdom of Saudi Arabia.,King Abdullah International Medical Research Center (KAIMRC), Riyadh, Kingdom of Saudi Arabia
| | - Mohammad A Khalil
- Department of Basic Medical Sciences, College of Medicine, King Fahid Medical City, Riyadh, Kingdom of Saudi Arabia
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19
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Zhu J, Yang LK, Chen WL, Lin W, Wang YH, Chen T. Activation of SK/K Ca Channel Attenuates Spinal Cord Ischemia-Reperfusion Injury via Anti-oxidative Activity and Inhibition of Mitochondrial Dysfunction in Rabbits. Front Pharmacol 2019; 10:325. [PMID: 31001121 PMCID: PMC6454010 DOI: 10.3389/fphar.2019.00325] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 03/19/2019] [Indexed: 11/25/2022] Open
Abstract
Spinal cord ischemia-reperfusion injury (SCI/R) is a rare but devastating disorder with a poor prognosis. Small conductance calcium-activated K+ (SK/KCa) channels are a family of voltage-independent potassium channels that are shown to participate in the pathological process of several neurological disorders. The aim of this study was to investigate the role of SK/KCa channels in experimental SCI/R in rabbits. The expression of SK/KCa1 protein significantly decreased in both cytoplasm and mitochondria in spinal cord tissues after SCI/R. Treatment with 2 mg/kg NS309, a pharmacological activator for SK/KCa channel, attenuated SCI/R-induced neuronal loss, spinal cord edema and neurological dysfunction. These effects were still observed when the administration was delayed by 6 h after SCI/R initiation. NS309 decreased the levels of oxidative products and promoted activities of antioxidant enzymes in both serum and spinal cord tissues. The results of ELISA assay showed that NS309 markedly decreased levels of pro-inflammatory cytokines while increased anti-inflammatory cytokines levels after SCI/R. In addition, treatment with NS309 was shown to preserve mitochondrial respiratory complexes activities and enhance mitochondrial biogenesis. The results of western blot analysis showed that NS309 differentially regulated the expression of mitochondrial dynamic proteins. In summary, our results demonstrated that the SK/KCa channel activator NS309 protects against SCI/R via anti-oxidative activity and inhibition of mitochondrial dysfunction, indicating a therapeutic potential of NS309 for SCI/R.
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Affiliation(s)
- Jie Zhu
- Department of Neurosurgery, The 101th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
| | - Li-Kun Yang
- Department of Neurosurgery, The 101th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
| | - Wei-Liang Chen
- Department of Neurosurgery, The 101th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
| | - Wei Lin
- Department of Neurosurgery, The 101th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
| | - Yu-Hai Wang
- Department of Neurosurgery, The 101th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
| | - Tao Chen
- Department of Neurosurgery, The 101th Hospital of PLA, School of Medicine, Anhui Medical University, Wuxi, China
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20
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Song Y, Zhu JS, Hua R, Du L, Huang ST, Stackman RW, Zhang G, Zhang YM. Small-Conductance Ca 2+-Activated K + Channel 2 in the Dorsal Horn of Spinal Cord Participates in Visceral Hypersensitivity in Rats. Front Pharmacol 2018; 9:840. [PMID: 30123129 PMCID: PMC6085475 DOI: 10.3389/fphar.2018.00840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/11/2018] [Indexed: 12/19/2022] Open
Abstract
Visceral hypersensitivity is a highly complex and subjective phenomenon associated with multiple levels of the nervous system and a wide range of neurotransmission. The dorsal horn (DH) in spinal cord relays the peripheral sensory information into the brain. Small conductance Ca2+-activated K+ (SK) channels regulate neuronal excitability and firing by allowing K+ to efflux in response to increase in the intracellular Ca2+ level. In this study, we examined the influence of SK2 channels in the spinal DH on the pathogenesis of visceral hypersensitivity induced by colorectal distension (CRD) in rats. Electrophysiological results showed that rats with visceral hypersensitivity presented a decrease in the SK channel-mediated afterhyperpolarization current (IAHP), and an increase in neuronal firing rates and c-Fos positive staining in the spinal DH. Western blot data revealed a decrease in the SK2 channel protein in the membrane fraction. Moreover, intrathecal administration of the SK2 channel activator 1-EBIO or CyPPA alleviated visceral hypersensitivity, reversed the decrease in IAHP and the increase in neuronal firing rates in spinal DH in rats that experienced CRD. 1-EBIO or CyPPA effect could be prevented by SK2 channel blocker apamin. CRD induced an increase in c-Fos protein expression in the spinal DH, which was prevented by 1-EBIO. Together, these data suggest that visceral hypersensitivity and pain is associated with a decrease in the number and function of membrane SK2 channels in the spinal DH. Pharmacological manipulation of SK2 channels may open a new avenue for the treatment of visceral hypersensitivity and pain. Highlights:Neonatal colorectal distension induced visceral hypersensitivity in rats. Visceral hypersensitivity rats presented a decrease in afterhyperpolarization current (IAHP) and membrane SK2 channel protein in the spinal dorsal horn. Visceral hypersensitivity rats presented an increase in neuronal firing rate in the spinal dorsal horn. Intrathecal administration of SK2 channel activator 1-EBIO or CyPPA prevented visceral hypersensitivity and decrease in IAHP.
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Affiliation(s)
- Yu Song
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Jun-Sheng Zhu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Rong Hua
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.,Emergency Department, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Lei Du
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Si-Ting Huang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Robert W Stackman
- Department of Psychology, Florida Atlantic University, Boca Raton, FL, United States
| | - Gongliang Zhang
- Department of Psychology, Florida Atlantic University, Boca Raton, FL, United States.,College of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yong-Mei Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China
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21
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Kshatri AS, Gonzalez-Hernandez A, Giraldez T. Physiological Roles and Therapeutic Potential of Ca 2+ Activated Potassium Channels in the Nervous System. Front Mol Neurosci 2018; 11:258. [PMID: 30104956 PMCID: PMC6077210 DOI: 10.3389/fnmol.2018.00258] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 07/06/2018] [Indexed: 12/21/2022] Open
Abstract
Within the potassium ion channel family, calcium activated potassium (KCa) channels are unique in their ability to couple intracellular Ca2+ signals to membrane potential variations. KCa channels are diversely distributed throughout the central nervous system and play fundamental roles ranging from regulating neuronal excitability to controlling neurotransmitter release. The physiological versatility of KCa channels is enhanced by alternative splicing and co-assembly with auxiliary subunits, leading to fundamental differences in distribution, subunit composition and pharmacological profiles. Thus, understanding specific KCa channels’ mechanisms in neuronal function is challenging. Based on their single channel conductance, KCa channels are divided into three subtypes: small (SK, 4–14 pS), intermediate (IK, 32–39 pS) and big potassium (BK, 200–300 pS) channels. This review describes the biophysical characteristics of these KCa channels, as well as their physiological roles and pathological implications. In addition, we also discuss the current pharmacological strategies and challenges to target KCa channels for the treatment of various neurological and psychiatric disorders.
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Affiliation(s)
- Aravind S Kshatri
- Department of Basic Medical Sciences, Medical School, Universidad de La Laguna, Tenerife, Spain.,Instituto de Tecnologias Biomedicas, Universidad de La Laguna, Tenerife, Spain
| | - Alberto Gonzalez-Hernandez
- Department of Basic Medical Sciences, Medical School, Universidad de La Laguna, Tenerife, Spain.,Instituto de Tecnologias Biomedicas, Universidad de La Laguna, Tenerife, Spain
| | - Teresa Giraldez
- Department of Basic Medical Sciences, Medical School, Universidad de La Laguna, Tenerife, Spain.,Instituto de Tecnologias Biomedicas, Universidad de La Laguna, Tenerife, Spain
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22
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Calcium-activated SK potassium channels are key modulators of the pacemaker frequency in locus coeruleus neurons. Mol Cell Neurosci 2018. [DOI: 10.1016/j.mcn.2018.03.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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23
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Chen X, Xue B, Wang J, Liu H, Shi L, Xie J. Potassium Channels: A Potential Therapeutic Target for Parkinson's Disease. Neurosci Bull 2017; 34:341-348. [PMID: 28884460 DOI: 10.1007/s12264-017-0177-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 06/22/2017] [Indexed: 12/21/2022] Open
Abstract
The pathogenesis of the second major neurodegenerative disorder, Parkinson's disease (PD), is closely associated with the dysfunction of potassium (K+) channels. Therefore, PD is also considered to be an ion channel disease or neuronal channelopathy. Mounting evidence has shown that K+ channels play crucial roles in the regulations of neurotransmitter release, neuronal excitability, and cell volume. Inhibition of K+ channels enhances the spontaneous firing frequency of nigral dopamine (DA) neurons, induces a transition from tonic firing to burst discharge, and promotes the release of DA in the striatum. Recently, three K+ channels have been identified to protect DA neurons and to improve the motor and non-motor symptoms in PD animal models: small conductance (SK) channels, A-type K+ channels, and KV7/KCNQ channels. In this review, we summarize the physiological and pharmacological effects of the three K+ channels. We also describe in detail the laboratory investigations regarding K+ channels as a potential therapeutic target for PD.
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Affiliation(s)
- Xiaoyan Chen
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Medical College of Qingdao University, Qingdao, 266071, China
| | - Bao Xue
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Medical College of Qingdao University, Qingdao, 266071, China
| | - Jun Wang
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Medical College of Qingdao University, Qingdao, 266071, China
| | - Haixia Liu
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Medical College of Qingdao University, Qingdao, 266071, China
| | - Limin Shi
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Medical College of Qingdao University, Qingdao, 266071, China.
| | - Junxia Xie
- Collaborative Innovation Center for Brain Science, Department of Physiology, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Medical College of Qingdao University, Qingdao, 266071, China.
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24
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Honrath B, Krabbendam IE, Culmsee C, Dolga AM. Small conductance Ca 2+-activated K + channels in the plasma membrane, mitochondria and the ER: Pharmacology and implications in neuronal diseases. Neurochem Int 2017; 109:13-23. [PMID: 28511953 DOI: 10.1016/j.neuint.2017.05.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/24/2017] [Accepted: 05/08/2017] [Indexed: 12/14/2022]
Abstract
Ca2+-activated K+ (KCa) channels regulate after-hyperpolarization in many types of neurons in the central and peripheral nervous system. Small conductance Ca2+-activated K+ (KCa2/SK) channels, a subfamily of KCa channels, are widely expressed in the nervous system, and in the cardiovascular system. Voltage-independent SK channels are activated by alterations in intracellular Ca2+ ([Ca2+]i) which facilitates the opening of these channels through binding of Ca2+ to calmodulin that is constitutively bound to the SK2 C-terminus. In neurons, SK channels regulate synaptic plasticity and [Ca2+]i homeostasis, and a number of recent studies elaborated on the emerging neuroprotective potential of SK channel activation in conditions of excitotoxicity and cerebral ischemia, as well as endoplasmic reticulum (ER) stress and oxidative cell death. Recently, SK channels were discovered in the inner mitochondrial membrane and in the membrane of the endoplasmic reticulum which sheds new light on the underlying molecular mechanisms and pathways involved in SK channel-mediated protective effects. In this review, we will discuss the protective properties of pharmacological SK channel modulation with particular emphasis on intracellularly located SK channels as potential therapeutic targets in paradigms of neuronal dysfunction.
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Affiliation(s)
- Birgit Honrath
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, 35043 Marburg, Germany; Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Department of Molecular Pharmacology, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Inge E Krabbendam
- Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Department of Molecular Pharmacology, University of Groningen, 9713 AV Groningen, The Netherlands
| | - Carsten Culmsee
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, 35043 Marburg, Germany
| | - Amalia M Dolga
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, 35043 Marburg, Germany; Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Department of Molecular Pharmacology, University of Groningen, 9713 AV Groningen, The Netherlands.
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25
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Honrath B, Matschke L, Meyer T, Magerhans L, Perocchi F, Ganjam GK, Zischka H, Krasel C, Gerding A, Bakker BM, Bünemann M, Strack S, Decher N, Culmsee C, Dolga AM. SK2 channels regulate mitochondrial respiration and mitochondrial Ca 2+ uptake. Cell Death Differ 2017; 24:761-773. [PMID: 28282037 DOI: 10.1038/cdd.2017.2] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/29/2016] [Accepted: 12/14/2016] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial calcium ([Ca2+]m) overload and changes in mitochondrial metabolism are key players in neuronal death. Small conductance calcium-activated potassium (SK) channels provide protection in different paradigms of neuronal cell death. Recently, SK channels were identified at the inner mitochondrial membrane, however, their particular role in the observed neuroprotection remains unclear. Here, we show a potential neuroprotective mechanism that involves attenuation of [Ca2+]m uptake upon SK channel activation as detected by time lapse mitochondrial Ca2+ measurements with the Ca2+-binding mitochondria-targeted aequorin and FRET-based [Ca2+]m probes. High-resolution respirometry revealed a reduction in mitochondrial respiration and complex I activity upon pharmacological activation and overexpression of mitochondrial SK2 channels resulting in reduced mitochondrial ROS formation. Overexpression of mitochondria-targeted SK2 channels enhanced mitochondrial resilience against neuronal death, and this effect was inhibited by overexpression of a mitochondria-targeted dominant-negative SK2 channel. These findings suggest that SK channels provide neuroprotection by reducing [Ca2+]m uptake and mitochondrial respiration in conditions, where sustained mitochondrial damage determines progressive neuronal death.
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Affiliation(s)
- Birgit Honrath
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany.,Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioural and Cognitive Neurosciences (BCN), Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Lina Matschke
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Tammo Meyer
- Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioural and Cognitive Neurosciences (BCN), Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Lena Magerhans
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Fabiana Perocchi
- Gene Center/Department of Biochemistry, Ludwig-Maximilians Universität München, Munich, Germany.,Institute for Obesity and Diabetes, Helmholtz Zentrum München, Neuherberg, Germany
| | - Goutham K Ganjam
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health GmbH, Neuherberg, Germany
| | - Cornelius Krasel
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Albert Gerding
- Center for Liver, Digestive and Metabolic Diseases, Department of Pediatrics & Systems Biology Center for Energy Metabolism and Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Barbara M Bakker
- Center for Liver, Digestive and Metabolic Diseases, Department of Pediatrics & Systems Biology Center for Energy Metabolism and Ageing, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Moritz Bünemann
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Stefan Strack
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, Marburg, Germany
| | - Carsten Culmsee
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany
| | - Amalia M Dolga
- Institute of Pharmacology and Clinical Pharmacy, University of Marburg, Marburg, Germany.,Faculty of Science and Engineering, Groningen Research Institute of Pharmacy, Behavioural and Cognitive Neurosciences (BCN), Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
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26
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Willis M, Trieb M, Leitner I, Wietzorrek G, Marksteiner J, Knaus HG. Small-conductance calcium-activated potassium type 2 channels (SK2, KCa2.2) in human brain. Brain Struct Funct 2016; 222:973-979. [PMID: 27357310 PMCID: PMC5334391 DOI: 10.1007/s00429-016-1258-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/20/2016] [Indexed: 12/02/2022]
Abstract
SK2 (KCa2.2) channels are voltage-independent Ca2+-activated K+ channels that regulate neuronal excitability in brain regions important for memory formation. In this study, we investigated the distribution and expression of SK2 channels in human brain by Western blot analysis and immunohistochemistry. Immunoblot analysis of human brain indicated expression of four distinct SK2 channel isoforms: the standard, the long and two short isoforms. Immunohistochemistry in paraffin-embedded post-mortem brain sections was performed in the hippocampal formation, amygdala and neocortex. In hippocampus, SK2-like immunoreactivity could be detected in strata oriens and radiatum of area CA1-CA2 and in the molecular layer. In the amygdala, SK2-like immunoreactivity was highest in the basolateral nuclei, while in neocortex, staining was mainly found enriched in layer V. Activation of SK2 channels is thought to regulate neuronal excitability in brain by contributing to the medium afterhyperpolarization. However, SK2 channels are blocked by apamin with a sensitivity that suggests heteromeric channels. The herein first shown expression of SK2 human isoform b in brain could explain the variability of electrophysiological findings observed with SK2 channels.
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Affiliation(s)
- Michael Willis
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical University Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria.
| | - Maria Trieb
- Division of Molecular and Cellular Pharmacology, Medical University Innsbruck, Peter Mayr Strasse 1, 6020, Innsbruck, Austria
| | - Irmgard Leitner
- Division of Molecular and Cellular Pharmacology, Medical University Innsbruck, Peter Mayr Strasse 1, 6020, Innsbruck, Austria
| | - Georg Wietzorrek
- Division of Molecular and Cellular Pharmacology, Medical University Innsbruck, Peter Mayr Strasse 1, 6020, Innsbruck, Austria
| | - Josef Marksteiner
- Department of Psychiatry and Psychotherapy A, Landeskrankenhaus Hall in Tirol, Milser Strasse 10, 6060, Hall in Tirol, Austria
| | - Hans-Günther Knaus
- Division of Molecular and Cellular Pharmacology, Medical University Innsbruck, Peter Mayr Strasse 1, 6020, Innsbruck, Austria
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27
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Abdulkareem ZA, Gee JMW, Cox CD, Wann KT. Knockdown of the small conductance Ca(2+) -activated K(+) channels is potently cytotoxic in breast cancer cell lines. Br J Pharmacol 2016; 173:177-90. [PMID: 26454020 PMCID: PMC4737296 DOI: 10.1111/bph.13357] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 08/27/2015] [Accepted: 09/24/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE Small conductance calcium-activated potassium (KCa 2.x) channels have a widely accepted canonical function in regulating cellular excitability. In this study, we address a potential non-canonical function of KCa 2.x channels in breast cancer cell survival, using in vitro models. EXPERIMENTAL APPROACH The expression of all KCa 2.x channel isoforms was initially probed using RT-PCR, Western blotting and microarray analysis in five widely studied breast cancer cell lines. In order to assess the effect of pharmacological blockade and siRNA-mediated knockdown of KCa 2.x channels on these cell lines, we utilized MTS proliferation assays and also followed the corresponding expression of apoptotic markers. KEY RESULTS All of the breast cancer cell lines, regardless of their lineage or endocrine responsiveness, were highly sensitive to KCa 2.x channel blockade. UCL1684 caused cytotoxicity, with LD50 values in the low nanomolar range, in all cell lines. The role of KCa 2.x channels was confirmed using pharmacological inhibition and siRNA-mediated knockdown. This reduced cell viability and also reduced expression of Bcl-2 but increased expression of active caspase-7 and caspase-9. Complementary to these results, a variety of cell lines can be protected from apoptosis induced by staurosporine using the KCa 2.x channel activator CyPPA. CONCLUSIONS AND IMPLICATIONS In addition to a well-established role for KCa 2.x channels in migration, blockade of these channels was potently cytotoxic in breast cancer cell lines, pointing to modulation of KCa 2.x channels as a potential therapeutic approach to breast cancer.
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Affiliation(s)
| | - Julia MW Gee
- School of Pharmacy and Pharmaceutical SciencesCardiff UniversityCardiffCF10 3NBUK
| | - Charles D Cox
- Victor Chang Cardiac Research InstituteDarlinghurstNSW2010Australia
| | - Kenneth T Wann
- School of Pharmacy and Pharmaceutical SciencesCardiff UniversityCardiffCF10 3NBUK
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28
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Firing Pattern Modulation Through SK Channel Current Increase Underlies Neuronal Survival in an Organotypic Slice Model of Parkinson’s Disease. Mol Neurobiol 2014; 51:424-36. [DOI: 10.1007/s12035-014-8728-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 04/29/2014] [Indexed: 12/28/2022]
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29
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Viana J, Pidsley R, Troakes C, Spiers H, Wong CC, Al-Sarraj S, Craig I, Schalkwyk L, Mill J. Epigenomic and transcriptomic signatures of a Klinefelter syndrome (47,XXY) karyotype in the brain. Epigenetics 2014; 9:587-99. [PMID: 24476718 PMCID: PMC4121369 DOI: 10.4161/epi.27806] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Klinefelter syndrome (KS) is the most common sex-chromosome aneuploidy in humans. Most affected individuals carry one extra X-chromosome (47,XXY karyotype) and the condition presents with a heterogeneous mix of reproductive, physical and psychiatric phenotypes. Although the mechanism(s) by which the supernumerary X-chromosome determines these features of KS are poorly understood, skewed X-chromosome inactivation (XCI), gene-dosage dysregulation, and the parental origin of the extra X-chromosome have all been implicated, suggesting an important role for epigenetic processes. We assessed genomic, methylomic and transcriptomic variation in matched prefrontal cortex and cerebellum samples identifying an individual with a 47,XXY karyotype who was comorbid for schizophrenia and had a notably reduced cerebellum mass compared with other individuals in the study (n = 49). We examined methylomic and transcriptomic differences in this individual relative to female and male samples with 46,XX or 46,XY karyotypes, respectively, and identified numerous locus-specific differences in DNA methylation and gene expression, with many differences being autosomal and tissue-specific. Furthermore, global DNA methylation, assessed via the interrogation of LINE-1 and Alu repetitive elements, was significantly altered in the 47,XXY patient in a tissue-specific manner with extreme hypomethylation detected in the prefrontal cortex and extreme hypermethylation in the cerebellum. This study provides the first detailed molecular characterization of the prefrontal cortex and cerebellum from an individual with a 47,XXY karyotype, identifying widespread tissue-specific epigenomic and transcriptomic alterations in the brain.
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Affiliation(s)
- Joana Viana
- University of Exeter Medical School; Exeter University; Exeter, UK
| | - Ruth Pidsley
- Institute of Psychiatry; King's College London; London, UK; Garvan Institute of Medical Research; Sydney, NSW Australia
| | - Claire Troakes
- Institute of Psychiatry; King's College London; London, UK
| | - Helen Spiers
- Institute of Psychiatry; King's College London; London, UK
| | - Chloe Cy Wong
- Institute of Psychiatry; King's College London; London, UK
| | - Safa Al-Sarraj
- Institute of Psychiatry; King's College London; London, UK
| | - Ian Craig
- Institute of Psychiatry; King's College London; London, UK
| | | | - Jonathan Mill
- University of Exeter Medical School; Exeter University; Exeter, UK; Institute of Psychiatry; King's College London; London, UK
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30
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Dolga AM, de Andrade A, Meissner L, Knaus HG, Höllerhage M, Christophersen P, Zischka H, Plesnila N, Höglinger GU, Culmsee C. Subcellular expression and neuroprotective effects of SK channels in human dopaminergic neurons. Cell Death Dis 2014; 5:e999. [PMID: 24434522 PMCID: PMC4040692 DOI: 10.1038/cddis.2013.530] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/23/2013] [Accepted: 11/27/2013] [Indexed: 12/21/2022]
Abstract
Small-conductance Ca(2+)-activated K(+) channel activation is an emerging therapeutic approach for treatment of neurological diseases, including stroke, amyotrophic lateral sclerosis and schizophrenia. Our previous studies showed that activation of SK channels exerted neuroprotective effects through inhibition of NMDAR-mediated excitotoxicity. In this study, we tested the therapeutic potential of SK channel activation of NS309 (25 μM) in cultured human postmitotic dopaminergic neurons in vitro conditionally immortalized and differentiated from human fetal mesencephalic cells. Quantitative RT-PCR and western blotting analysis showed that differentiated dopaminergic neurons expressed low levels of SK2 channels and high levels of SK1 and SK3 channels. Further, protein analysis of subcellular fractions revealed expression of SK2 channel subtype in mitochondrial-enriched fraction. Mitochondrial complex I inhibitor rotenone (0.5 μM) disrupted the dendritic network of human dopaminergic neurons and induced neuronal death. SK channel activation reduced mitochondrial membrane potential, while it preserved the dendritic network, cell viability and ATP levels after rotenone challenge. Mitochondrial dysfunction and delayed dopaminergic cell death were prevented by increasing and/or stabilizing SK channel activity. Overall, our findings show that activation of SK channels provides protective effects in human dopaminergic neurons, likely via activation of both membrane and mitochondrial SK channels. Thus, SK channels are promising therapeutic targets for neurodegenerative disorders such as Parkinson's disease, where dopaminergic cell loss is associated with progression of the disease.
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Affiliation(s)
- A M Dolga
- Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, Marburg, Germany
| | - A de Andrade
- Experimental Neurology, Philipps-Universität Marburg, Marburg, Germany
| | - L Meissner
- Institute of Stroke and Dementia Research, University of Munich Medical School, Munich, Germany
| | - H-G Knaus
- Department for Medical Genetics, Molecular and Clinical Pharmacology, Innsbruck Medical University, Innsbruck, Austria
| | - M Höllerhage
- Experimental Neurology, Philipps-Universität Marburg, Marburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Department of Neurology, Technical University Munich, Munich, Germany
| | | | - H Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München–German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - N Plesnila
- Institute of Stroke and Dementia Research, University of Munich Medical School, Munich, Germany
| | - G U Höglinger
- Experimental Neurology, Philipps-Universität Marburg, Marburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Department of Neurology, Technical University Munich, Munich, Germany
| | - C Culmsee
- Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, Marburg, Germany
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31
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Microglial ion channels as potential targets for neuroprotection in Parkinson's disease. Neural Plast 2013; 2013:587418. [PMID: 24288626 PMCID: PMC3832972 DOI: 10.1155/2013/587418] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/19/2013] [Indexed: 12/13/2022] Open
Abstract
Parkinson's disease (PD) is a chronic, degenerative neurological disorder that is estimated to affect at least 1 million individuals in the USA and over 10 million worldwide. It is thought that the loss of neurons and development of inclusion bodies occur gradually over decades until they progress to the point where ~60% of the dopamine neurons are lost and patients present with motor dysfunction. At present, it is not clear what causes this progression, and there are no current therapies that have been successful in preventing PD progression. Although there are many hypotheses regarding the mechanism of PD progression, neuroinflammation may be a major contributor to PD pathogenesis. Indeed, activated microglia and subsequent neuroinflammation have been consistently associated with the pathogenesis of PD. Thus, interference with this process could provide a means of neuroprotection in PD. This review will discuss the potential of targeting microglia to reduce neuroinflammation in PD. Further, we discuss the potential of microglial ion channels to serve as novel targets for neuroprotection in PD.
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32
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Imbrici P, Camerino DC, Tricarico D. Major channels involved in neuropsychiatric disorders and therapeutic perspectives. Front Genet 2013; 4:76. [PMID: 23675382 PMCID: PMC3646240 DOI: 10.3389/fgene.2013.00076] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/16/2013] [Indexed: 12/11/2022] Open
Abstract
Voltage-gated ion channels are important mediators of physiological functions in the central nervous system. The cyclic activation of these channels influences neurotransmitter release, neuron excitability, gene transcription, and plasticity, providing distinct brain areas with unique physiological and pharmacological response. A growing body of data has implicated ion channels in the susceptibility or pathogenesis of psychiatric diseases. Indeed, population studies support the association of polymorphisms in calcium and potassium channels with the genetic risk for bipolar disorders (BPDs) or schizophrenia. Moreover, point mutations in calcium, sodium, and potassium channel genes have been identified in some childhood developmental disorders. Finally, antibodies against potassium channel complexes occur in a series of autoimmune psychiatric diseases. Here we report recent studies assessing the role of calcium, sodium, and potassium channels in BPD, schizophrenia, and autism spectrum disorders, and briefly summarize promising pharmacological strategies targeted on ion channels for the therapy of mental illness and related genetic tests.
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Affiliation(s)
- Paola Imbrici
- Section of Pharmacology, Department of Pharmacy - Drug Science, University of Bari Bari, Italy
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33
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Dolga AM, Netter MF, Perocchi F, Doti N, Meissner L, Tobaben S, Grohm J, Zischka H, Plesnila N, Decher N, Culmsee C. Mitochondrial small conductance SK2 channels prevent glutamate-induced oxytosis and mitochondrial dysfunction. J Biol Chem 2013; 288:10792-804. [PMID: 23430260 PMCID: PMC3624460 DOI: 10.1074/jbc.m113.453522] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 02/08/2013] [Indexed: 11/06/2022] Open
Abstract
Small conductance calcium-activated potassium (SK2/K(Ca)2.2) channels are known to be located in the neuronal plasma membrane where they provide feedback control of NMDA receptor activity. Here, we provide evidence that SK2 channels are also located in the inner mitochondrial membrane of neuronal mitochondria. Patch clamp recordings in isolated mitoplasts suggest insertion into the inner mitochondrial membrane with the C and N termini facing the intermembrane space. Activation of SK channels increased mitochondrial K(+) currents, whereas channel inhibition attenuated these currents. In a model of glutamate toxicity, activation of SK2 channels attenuated the loss of the mitochondrial transmembrane potential, blocked mitochondrial fission, prevented the release of proapoptotic mitochondrial proteins, and reduced cell death. Neuroprotection was blocked by specific SK2 inhibitory peptides and siRNA targeting SK2 channels. Activation of mitochondrial SK2 channels may therefore represent promising targets for neuroprotective strategies in conditions of mitochondrial dysfunction.
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Affiliation(s)
- Amalia M. Dolga
- From the Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, D-35032 Marburg, Germany
| | - Michael F. Netter
- Institut für Physiologie und Pathophysiologie, Vegetative Physiologie, Fachbereich Medizin, Philipps-Universität Marburg, D-35037 Marburg, Germany
| | - Fabiana Perocchi
- Department of Systems Biology and Medicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
- Gene Center, Ludwig Maximilians University, Feodor-Lynen Strasse 25, 81377 Munich, Germany
| | - Nunzianna Doti
- From the Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, D-35032 Marburg, Germany
- Department of Neurodegeneration, Royal College of Surgeons in Ireland, Dublin 2, Ireland
- Institute of Biostructures and Bioimaging, National Research Council (CNR), 16-80131 Naples, Italy
| | - Lilja Meissner
- Institute of Stroke and Dementia Research, University of Munich Medical School, D-81377 Munich, Germany, and
| | - Svenja Tobaben
- From the Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, D-35032 Marburg, Germany
| | - Julia Grohm
- From the Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, D-35032 Marburg, Germany
| | - Hans Zischka
- Institute of Toxicology, Helmholtz Zentrum München-German Research Center for Environmental Health (GmbH), D-85764 Neuherberg, Germany
| | - Nikolaus Plesnila
- Department of Neurodegeneration, Royal College of Surgeons in Ireland, Dublin 2, Ireland
- Institute of Stroke and Dementia Research, University of Munich Medical School, D-81377 Munich, Germany, and
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, Vegetative Physiologie, Fachbereich Medizin, Philipps-Universität Marburg, D-35037 Marburg, Germany
| | - Carsten Culmsee
- From the Institut für Pharmakologie und Klinische Pharmazie, Fachbereich Pharmazie, Philipps-Universität Marburg, D-35032 Marburg, Germany
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