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Huang S, Dong W, Lin X, Bian J. Na+/K+-ATPase: ion pump, signal transducer, or cytoprotective protein, and novel biological functions. Neural Regen Res 2024; 19:2684-2697. [PMID: 38595287 PMCID: PMC11168508 DOI: 10.4103/nrr.nrr-d-23-01175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/23/2023] [Accepted: 12/09/2023] [Indexed: 04/11/2024] Open
Abstract
Na+/K+-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na+ out of and two K+ into cells. Additionally, Na+/K+-ATPase participates in Ca2+-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane. Na+/K+-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells. Therefore, it is not surprising that Na+/K+-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases. However, published studies have so far only elucidated the important roles of Na+/K+-ATPase dysfunction in disease development, and we are lacking detailed mechanisms to clarify how Na+/K+-ATPase affects cell function. Our recent studies revealed that membrane loss of Na+/K+-ATPase is a key mechanism in many neurological disorders, particularly stroke and Parkinson's disease. Stabilization of plasma membrane Na+/K+-ATPase with an antibody is a novel strategy to treat these diseases. For this reason, Na+/K+-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein, participating in signal transduction such as neuronal autophagy and apoptosis, and glial cell migration. Thus, the present review attempts to summarize the novel biological functions of Na+/K+-ATPase and Na+/K+-ATPase-related pathogenesis. The potential for novel strategies to treat Na+/K+-ATPase-related brain diseases will also be discussed.
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Affiliation(s)
- Songqiang Huang
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Wanting Dong
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Xiaoqian Lin
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Jinsong Bian
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
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Miyata S, Tsuda M, Mitsui S. Overexpression of Motopsin, an Extracellular Serine Protease Related to Intellectual Disability, Promotes Adult Neurogenesis and Neuronal Responsiveness in the Dentate Gyrus. Mol Neurobiol 2024; 61:4929-4948. [PMID: 38153682 DOI: 10.1007/s12035-023-03890-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 12/18/2023] [Indexed: 12/29/2023]
Abstract
Motopsin, a serine protease encoded by PRSS12, is secreted by neuronal cells into the synaptic clefts in an activity-dependent manner, where it induces synaptogenesis by modulating Na+/K+-ATPase activity. In humans, motopsin deficiency leads to severe intellectual disability and, in mice, it disturbs spatial memory and social behavior. In this study, we investigated mice that overexpressed motopsin in the forebrain using the Tet-Off system (DTG-OE mice). The elevated agrin cleavage or the reduced Na+/K+-ATPase activity was not detected. However, motopsin overexpression led to a reduction in spine density in hippocampal CA1 basal dendrites. While motopsin overexpression decreased the ratio of mature mushroom spines in the DG, it increased the ratio of immature thin spines in CA1 apical dendrites. Female DTG-OE mice showed elevated locomotor activity in their home cages. DTG-OE mice showed aberrant behaviors, such as delayed latency to the target hole in the Barnes maze test and prolonged duration of sniffing objects in the novel object recognition test (NOR), although they retained memory comparable to that of TRE-motopsin littermates, which normally express motopsin. After NOR, c-Fos-positive cells increased in the dentate gyrus (DG) of DTG-OE mice compared with that of DTG-SO littermates, in which motopsin overexpression was suppressed by the administration of doxycycline, and TRE-motopsin littermates. Notably, the numbers of doublecortin- and 5-bromo-2'-deoxyuridine-labeled cells significantly increased in the DG of DTG-OE mice, suggesting increased adult neurogenesis. Importantly, our results revealed a new function in addition to modulating neuronal responsiveness and spine morphology in the DG: the regulation of neurogenesis.
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Affiliation(s)
- Shiori Miyata
- Department of Rehabilitation Sciences, Gunma University Graduate School of Health Sciences, 3-39-22 Showa, Maebashi, Gunma, 371-8514, Japan
| | - Masayuki Tsuda
- Division of Laboratory Animal Science, Science Research Center, Kochi Medical School, Kochi University, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Shinichi Mitsui
- Department of Rehabilitation Sciences, Gunma University Graduate School of Health Sciences, 3-39-22 Showa, Maebashi, Gunma, 371-8514, Japan.
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de Melo AD, Freire VAF, Diogo ÍL, Santos HDL, Barbosa LA, de Carvalho LED. Antioxidant Therapy Reduces Oxidative Stress, Restores Na,K-ATPase Function and Induces Neuroprotection in Rodent Models of Seizure and Epilepsy: A Systematic Review and Meta-Analysis. Antioxidants (Basel) 2023; 12:1397. [PMID: 37507936 PMCID: PMC10376594 DOI: 10.3390/antiox12071397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 07/30/2023] Open
Abstract
Epilepsy is a neurological disorder characterized by epileptic seizures resulting from neuronal hyperexcitability, which may be related to failures in Na,K-ATPase activity and oxidative stress participation. We conducted this study to investigate the impact of antioxidant therapy on oxidative stress, Na,K-ATPase activity, seizure factors, and mortality in rodent seizure/epilepsy models induced by pentylenetetrazol (PTZ), pilocarpine (PILO), and kainic acid (KA). After screening 561 records in the MEDLINE, EMBASE, Web of Science, Science Direct, and Scopus databases, 22 were included in the systematic review following the PRISMA guidelines. The meta-analysis included 14 studies and showed that in epileptic animals there was an increase in the oxidizing agents nitric oxide (NO) and malondialdehyde (MDA), with a reduction in endogenous antioxidants reduced glutathione (GSH) and superoxide dismutase (SO). The Na,K-ATPase activity was reduced in all areas evaluated. Antioxidant therapy reversed all of these parameters altered by seizure or epilepsy induction. In addition, there was a percentage decrease in the number of seizures and mortality, and a meta-analysis showed a longer seizure latency in animals using antioxidant therapy. Thus, this study suggests that the use of antioxidants promotes neuroprotective effects and mitigates the effects of epilepsy. The protocol was registered in the Prospective Register of Systematic Reviews (PROSPERO) CRD42022356960.
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Affiliation(s)
- Anderson Dutra de Melo
- Departamento de Ciências e Linguagens, Instituto Federal de Minas Gerais, Bambui 38900-000, Minas Gerais, Brazil
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Victor Antonio Ferreira Freire
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Ítalo Leonardo Diogo
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Hérica de Lima Santos
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Leandro Augusto Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
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Crespo M, León-Navarro DA, Martín M. Na +/K +- and Mg 2+-ATPases and Their Interaction with AMPA, NMDA and D 2 Dopamine Receptors in an Animal Model of Febrile Seizures. Int J Mol Sci 2022; 23:ijms232314638. [PMID: 36498965 PMCID: PMC9737571 DOI: 10.3390/ijms232314638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/05/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
Abstract
Febrile seizures (FS) are one of the most common seizure disorders in childhood which are classified into short and prolonged, depending on their duration. Short FS are usually considered as benign. However, epidemiological studies have shown an association between prolonged FS and temporal lobe epilepsy. The development of animal models of FS has been very useful to investigate the mechanisms and the consequences of FS. One of the most used, the "hair dryer model", has revealed that prolonged FS may lead to temporal lobe epilepsy by altering neuronal function. Several pieces of evidence suggest that Na+/ K+-ATPase and Mg2+-ATPase may play a role in this epileptogenic process. In this work, we found that hyperthermia-induced seizures (HIS) significantly increased the activity of Na+/ K+-ATPase and Mg2+-ATPase five and twenty days after hyperthermic insult, respectively. These effects were diminished in response to AMPA, D2 dopamine A1 and A2A receptors activation, respectively. Furthermore, HIS also significantly increased the protein level of the AMPA subunit GluR1. Altogether, the increased Na+/ K+-ATPase and Mg2+-ATPase agree well with the presence of protective mechanisms. However, the reduction in ATPase activities in the presence of NMDA and AMPA suggest an increased propensity for epileptic events in adults.
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Affiliation(s)
- María Crespo
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - David Agustín León-Navarro
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
- Correspondence: ; Tel.: +34-926-052-114
| | - Mairena Martín
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
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Sun J, Zheng Y, Chen Z, Wang Y. The role of Na + -K + -ATPase in the epileptic brain. CNS Neurosci Ther 2022; 28:1294-1302. [PMID: 35751846 PMCID: PMC9344081 DOI: 10.1111/cns.13893] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 11/26/2022] Open
Abstract
Na+-K+-ATPase, a P-type ATP-powered ion transporter on cell membrane, plays a vital role in cellular excitability. Cellular hyperexcitability, accompanied by hypersynchronous firing, is an important basis for seizures/epilepsy. An increasing number of studies point to a significant contribution of Na+-K+-ATPase to epilepsy, although discordant results exist. In this review, we comprehensively summarize the structure and physiological function of Na+-K+-ATPase in the central nervous system and critically evaluate the role of Na+-K+-ATPase in the epileptic brain. Importantly, we further provide perspectives on some possible research directions and discuss its potential as a therapeutic target for the treatment of epilepsy.
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Affiliation(s)
- Jinyi Sun
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yang Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Vogt AG, de Oliveira RL, Voss GT, Blödorn GB, Alves D, Wilhelm EA, Luchese C. QCTA-1, a quinoline derivative, ameliorates pentylenetetrazole-induced kindling and memory comorbidity in mice: Involvement of antioxidant system of brain. Pharmacol Biochem Behav 2022; 215:173357. [DOI: 10.1016/j.pbb.2022.173357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 01/19/2023]
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Jing YP, An H, Zhang S, Wang N, Zhou S. Protein kinase C mediates juvenile hormone-dependent phosphorylation of Na +/K +-ATPase to induce ovarian follicular patency for yolk protein uptake. J Biol Chem 2018; 293:20112-20122. [PMID: 30385509 DOI: 10.1074/jbc.ra118.005692] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/11/2018] [Indexed: 12/21/2022] Open
Abstract
In oviparous animals, vitellogenesis is prerequisite to egg production and embryonic growth after oviposition. For successful insect vitellogenesis and oogenesis, vitellogenin (Vg) synthesized in the fat body (homologue to vertebrate liver and adipose tissue) must pass through the intercellular channels, a condition known as patency in the follicular epithelium, to reach the surface of oocytes. This process is controlled by juvenile hormone (JH) in many insect species, but the underlying mechanisms remain elusive. Previous work has suggested the possible involvement of Na+/K+-ATPase in patency initiation, but again, the regulatory cascade of Na+/K+-ATPase for patency initiation has been lacking. Using the migratory locust Locusta migratoria as a model system, we report here that RNAi-mediated knockdown of gene coding for Na+/K+-ATPase, inhibition of its phosphorylation, or suppression of its activity causes loss of patency, resulting in blocked Vg uptake, arrested oocyte maturation, and impaired ovarian growth. JH triggers G protein-coupled receptor (GPCR), receptor tyrosine kinase (RTK), phospholipase C (PLC), inositol trisphosphate receptor (IP3R), and protein kinase C (PKC) to phosphorylate Na+/K+-ATPase α-subunit at amino acid residue Ser8, consequently activating Na+/K+-ATPase for the induction of patency in vitellogenic follicular epithelium. Our results thus point to a previously unidentified mechanism by which JH induces the phosphorylation and activation of Na+/K+-ATPase via a signaling cascade of GPCR, RTK, PLC, IP3R, and PKC. The findings advance our understanding of JH regulation in insect vitellogenesis and oogenesis.
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Affiliation(s)
- Yu-Pu Jing
- From the Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Hongli An
- From the Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Shanjing Zhang
- From the Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Ningbo Wang
- From the Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Shutang Zhou
- From the Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China.
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Germline De Novo Mutations in ATP1A1 Cause Renal Hypomagnesemia, Refractory Seizures, and Intellectual Disability. Am J Hum Genet 2018; 103:808-816. [PMID: 30388404 DOI: 10.1016/j.ajhg.2018.10.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/01/2018] [Indexed: 12/22/2022] Open
Abstract
Over the last decades, a growing spectrum of monogenic disorders of human magnesium homeostasis has been clinically characterized, and genetic studies in affected individuals have identified important molecular components of cellular and epithelial magnesium transport. Here, we describe three infants who are from non-consanguineous families and who presented with a disease phenotype consisting of generalized seizures in infancy, severe hypomagnesemia, and renal magnesium wasting. Seizures persisted despite magnesium supplementation and were associated with significant intellectual disability. Whole-exome sequencing and conventional Sanger sequencing identified heterozygous de novo mutations in the catalytic Na+, K+-ATPase α1 subunit (ATP1A1). Functional characterization of mutant Na+, K+-ATPase α1 subunits in heterologous expression systems revealed not only a loss of Na+, K+-ATPase function but also abnormal cation permeabilities, which led to membrane depolarization and possibly aggravated the effect of the loss of physiological pump activity. These findings underline the indispensable role of the α1 isoform of the Na+, K+-ATPase for renal-tubular magnesium handling and cellular ion homeostasis, as well as maintenance of physiologic neuronal activity.
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Holm TH, Lykke-Hartmann K. Insights into the Pathology of the α3 Na(+)/K(+)-ATPase Ion Pump in Neurological Disorders; Lessons from Animal Models. Front Physiol 2016; 7:209. [PMID: 27378932 PMCID: PMC4906016 DOI: 10.3389/fphys.2016.00209] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 05/22/2016] [Indexed: 01/08/2023] Open
Abstract
The transmembrane Na(+)-/K(+) ATPase is located at the plasma membrane of all mammalian cells. The Na(+)-/K(+) ATPase utilizes energy from ATP hydrolysis to extrude three Na(+) cations and import two K(+) cations into the cell. The minimum constellation for an active Na(+)-/K(+) ATPase is one alpha (α) and one beta (β) subunit. Mammals express four α isoforms (α1-4), encoded by the ATP1A1-4 genes, respectively. The α1 isoform is ubiquitously expressed in the adult central nervous system (CNS) whereas α2 primarily is expressed in astrocytes and α3 in neurons. Na(+) and K(+) are the principal ions involved in action potential propagation during neuronal depolarization. The α1 and α3 Na(+)-/K(+) ATPases are therefore prime candidates for restoring neuronal membrane potential after depolarization and for maintaining neuronal excitability. The α3 isoform has approximately four-fold lower Na(+) affinity compared to α1 and is specifically required for rapid restoration of large transient increases in [Na(+)]i. Conditions associated with α3 deficiency are therefore likely aggravated by suprathreshold neuronal activity. The α3 isoform been suggested to support re-uptake of neurotransmitters. These processes are required for normal brain activity, and in fact autosomal dominant de novo mutations in ATP1A3 encoding the α3 isoform has been found to cause the three neurological diseases Rapid Onset Dystonia Parkinsonism (RDP), Alternating Hemiplegia of Childhood (AHC), and Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). All three diseases cause acute onset of neurological symptoms, but the predominant neurological manifestations differ with particularly early onset of hemiplegic/dystonic episodes and mental decline in AHC, ataxic encephalopathy and impairment of vision and hearing in CAPOS syndrome and late onset of dystonia/parkinsonism in RDP. Several mouse models have been generated to study the in vivo consequences of Atp1a3 modulation. The different mice show varying degrees of hyperactivity, gait problems, and learning disability as well as stress-induced seizures. With the advent of several Atp1a3-gene or chemically modified animal models that closely phenocopy many aspects of the human disorders, we will be able to reach a much better understanding of the etiology of RDP, AHC, and CAPOS syndrome.
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Affiliation(s)
- Thomas H. Holm
- Department of Biomedicine, Aarhus UniversityAarhus, Denmark
- Department of Molecular Biology and Genetics, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Aarhus UniversityAarhus, Denmark
| | - Karin Lykke-Hartmann
- Department of Biomedicine, Aarhus UniversityAarhus, Denmark
- Department of Molecular Biology and Genetics, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Aarhus UniversityAarhus, Denmark
- Aarhus Institute of Advanced Studies, Aarhus UniversityAarhus, Denmark
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Funck V, Ribeiro L, Pereira L, de Oliveira C, Grigoletto J, Della-Pace I, Fighera M, Royes L, Furian A, Larrick J, Oliveira M. Contrasting effects of Na+, K+-ATPase activation on seizure activity in acute versus chronic models. Neuroscience 2015; 298:171-9. [DOI: 10.1016/j.neuroscience.2015.04.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 03/02/2015] [Accepted: 04/14/2015] [Indexed: 10/23/2022]
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Sütt S, Altpere A, Reimets R, Visnapuu T, Loomets M, Raud S, Salum T, Mahlapuu R, Kairane C, Zilmer M, Vasar E. Wfs1-deficient animals have brain-region-specific changes of Na+, K+-ATPase activity and mRNA expression of α1 and β1 subunits. J Neurosci Res 2014; 93:530-7. [PMID: 25385034 DOI: 10.1002/jnr.23508] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 09/09/2014] [Accepted: 09/29/2014] [Indexed: 12/20/2022]
Abstract
Mutations in the WFS1 gene, which encodes the endoplasmic reticulum (ER) glycoprotein, cause Wolfram syndrome, a disease characterized by juvenile-onset diabetes mellitus, optic atrophy, deafness, and different psychiatric abnormalities. Loss of neuronal cells and pancreatic β-cells in Wolfram syndrome patients is probably related to the dysfunction of ER stress regulation, which leads to cell apoptosis. The present study shows that Wfs1-deficient mice have brain-region-specific changes in Na(+),K(+)-ATPase activity and in the expression of the α1 and β1 subunits. We found a significant (1.6-fold) increase of Na-pump activity and β1 subunit mRNA expression in mice lacking the Wfs1 gene in the temporal lobe compared with their wild-type littermates. By contrast, exposure of mice to the elevated plus maze (EPM) model of anxiety decreased Na-pump activity 1.3-fold in the midbrain and dorsal striatum and 2.0-fold in the ventral striatum of homozygous animals compared with the nonexposed group. Na-pump α1 -subunit mRNA was significantly decreased in the dorsal striatum and midbrain of Wfs1-deficient homozygous animals compared with wild-type littermates. In the temporal lobe, an increase in the activity of the Na-pump is probably related to increased anxiety established in Wfs1-deficient mice, whereas the blunted dopamine function in the forebrain of Wfs1-deficient mice may be associated with a decrease of Na-pump activity in the dorsal and ventral striatum and in the midbrain after exposure to the EPM.
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Affiliation(s)
- S Sütt
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence for Translational Medicine, Tartu, Estonia
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Funck VR, Ribeiro LR, Pereira LM, de Oliveira CV, Grigoletto J, Fighera MR, Royes LFF, Furian AF, Oliveira MS. Long-term decrease in Na+,K+-ATPase activity after pilocarpine-induced status epilepticus is associated with nitration of its alpha subunit. Epilepsy Res 2014; 108:1705-10. [PMID: 25311690 DOI: 10.1016/j.eplepsyres.2014.09.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/20/2014] [Accepted: 09/21/2014] [Indexed: 11/30/2022]
Abstract
Temporal lobe epilepsy (TLE) is the most common type of epilepsy with about one third of TLE patients being refractory to antiepileptic drugs. Knowledge about the mechanisms underlying seizure activity is fundamental to the discovery of new drug targets. Brain Na(+),K(+)-ATPase activity contributes to the maintenance of the electrochemical gradients underlying neuronal resting and action potentials as well as the uptake and release of neurotransmitters. In the present study we tested the hypothesis that decreased Na(+),K(+)-ATPase activity is associated with changes in the alpha subunit phosphorylation and/or redox state. Activity of Na(+),K(+)-ATPase decreased in the hippocampus of C57BL/6 mice 60 days after pilocarpine-induced status epilepticus (SE). In addition, the Michaelis-Menten constant for ATP of α2/3 isoforms increased at the same time point. Nitration of the α subunit may underlie decreased Na(+),K(+)-ATPase activity, however no changes in expression or phosphorylation state at Ser(943) were found. Further studies are necessary define the potential of nitrated Na(+),K(+)-ATPase as a new therapeutic target for seizure disorders.
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Affiliation(s)
- Vinícius Rafael Funck
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | | | - Letícia Meier Pereira
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | | | - Jéssica Grigoletto
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Michele Rechia Fighera
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Biological Sciences: Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil
| | - Luiz Fernando Freire Royes
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Biological Sciences: Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil
| | - Ana Flávia Furian
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil
| | - Mauro Schneider Oliveira
- Graduate Program in Pharmacology, Federal University of Santa Maria, Santa Maria, Brazil; Graduate Program in Biological Sciences: Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil.
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Vilela LR, Medeiros DC, de Oliveira ACP, Moraes MF, Moreira FA. Anticonvulsant effects of N-arachidonoyl-serotonin, a dual fatty acid amide hydrolase enzyme and transient receptor potential vanilloid type-1 (TRPV1) channel blocker, on experimental seizures: the roles of cannabinoid CB1 receptors and TRPV1 channels. Basic Clin Pharmacol Toxicol 2014; 115:330-4. [PMID: 24674273 DOI: 10.1111/bcpt.12232] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/04/2014] [Indexed: 01/21/2023]
Abstract
Selective blockade of anandamide hydrolysis, through the inhibition of the FAAH enzyme, has anticonvulsant effects, which are mediated by CB1 receptors. Anandamide, however, also activates TRPV1 channels, generally with an opposite outcome on neuronal modulation. Thus, we suggested that the dual FAAH and TRPV1 blockade with N-arachidonoyl-serotonin (AA-5-HT) would be efficacious in inhibiting pentylenetetrazole (PTZ)-induced seizures in mice. We also investigated the contribution of CB1 activation and TRPV1 blockade to the overt effect of AA-5-HT. In the first experiment, injection of AA-5-HT (0.3-3.0 mg/kg) delayed the onset and reduced the duration of PTZ (60 mg)-induced seizures in mice. These effects were reversed by pre-treatment with the CB1 antagonist, AM251 (1.0-3.0 mg/kg). Finally, we observed that administration of the selective TRPV1 antagonist, SB366791 (0.1-1 mg/kg), did not entirely mimic AA-5-HT effects. In conclusion, AA-5-HT alleviates seizures in mice, an effect inhibited by CB1 antagonism, but not completely mimicked by TRPV1 blockage, indicating that the overall effect of AA-5-HT seems to depend mainly on CB1 receptors. This may represent a new strategy for the development of drugs against seizures, epilepsies and related syndromes.
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Affiliation(s)
- Luciano R Vilela
- Graduate School in Neuroscience, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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