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Nakamura-Maruyama E, Kai R, Himi N, Okabe N, Narita K, Miyazaki T, Aoki S, Miyamoto O. Ryanodine receptors are involved in the improvement of depression-like behaviors through electroconvulsive shock in stressed mice. Brain Stimul 2020; 14:36-47. [PMID: 33166727 DOI: 10.1016/j.brs.2020.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/20/2020] [Accepted: 11/01/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Electroconvulsive therapy (ECT) is effective for treating depression. However, the mechanisms underlying the antidepressant effects of ECT remain unknown. Depressed patients exhibit abnormal Ca2+ kinetics. Early stages of the intracellular Ca2+ signaling pathway involve the release of Ca2+ from the endoplasmic reticulum (ER) via Ca2+ release channels. OBJECTIVE We considered that depression may be improved via ECT-induced normalization of intracellular Ca2+ regulation through the Ca2+ release channels. The current study aimed to investigate the effects of ECT on two Ca2+ release channels, ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (IP3Rs). METHODS A mouse depression-like model subjected to water immersion with restraint stress was administered electroconvulsive shock (ECS) therapy. Their depression-like status was behaviorally and histologically assessed using forced swimming tests, novelty-suppressed feeding tests, and by evaluating neurogenesis in the hippocampal dentate gyrus, respectively. A RyRs blocker, dantrolene, was administered prior to ECS, and the changes in depression-like conditions were examined. RESULTS The protein expressions of RyR1 and RyR3 significantly increased in the hippocampus of the mouse model with depression-like symptoms. This increase was attenuated as depression-like symptoms were reduced due to ECS application. However, pre-injection with dantrolene reduced the antidepressant effects of ECS. CONCLUSIONS A significant increase in RyRs expression in a depression-like state and exacerbation of depression-like symptoms by RyRs inhibitors may be caused by RyRs dysfunction, suggesting overexpression of RyRs is a compensatory effect. Normalization of RyRs expression levels by ECS suggests that ECT normalizes the Ca2+ release via RyRs. Thus, normalizing the function of RyRs may play an important role in the therapeutic effect of ECT.
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Affiliation(s)
| | - Risa Kai
- Department of Physiology 2, Kawasaki Medical School, Kurashiki, Japan
| | - Naoyuki Himi
- Department of Physiology 2, Kawasaki Medical School, Kurashiki, Japan
| | - Naohiko Okabe
- Department of Physiology 2, Kawasaki Medical School, Kurashiki, Japan
| | - Kazuhiko Narita
- Department of Physiology 2, Kawasaki Medical School, Kurashiki, Japan
| | - Tetsuji Miyazaki
- Department of Psychiatry, Kawasaki Medical School, Kurashiki, Japan
| | - Shozo Aoki
- Department of Psychiatry, Kawasaki Medical School, Kurashiki, Japan
| | - Osamu Miyamoto
- Department of Physiology 2, Kawasaki Medical School, Kurashiki, Japan.
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2
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Post JI, Leergaard TB, Ratz V, Walaas SI, von Hörsten S, Nissen-Meyer LSH. Differential Levels and Phosphorylation of Type 1 Inositol 1,4,5-Trisphosphate Receptor in Four Different Murine Models of Huntington Disease. J Huntingtons Dis 2019; 8:271-289. [PMID: 31256144 DOI: 10.3233/jhd-180301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The intracellular ion channel type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) releases Ca2+ from the endoplasmic reticulum upon stimulation with IP3. Perturbation of IP3R1 has been implicated in the development of several neurodegenerative disorders, including Huntington disease (HD). OBJECTIVE To elucidate the putative role of IP3R1 phosphorylation in HD, we investigated IP3R1 levels and protein phosphorylation state in the striatum, hippocampus and cerebellum of four murine HD models. METHODS Quantitative immunoblotting with antibodies to IP3R1 protein and its phosphorylated serines 1589 and 1755 was applied to brain homogenates from R6/1 mice to study early-onset aggressive HD. To determine if IP3R1 changes precede overt pathology, we immunostained tissues from the regions of interest and several control regions for IP3R1 in tgHDCAG51n rats and BACHD and zQ175DNKI mice, all recognized models for late-onset HD. RESULTS R6/1 mice had reduced total IP3R1 immunoreactivity, variably reduced serine1755-phosphorylation in all regions investigated, and reduced serine1589-phosphorylation in cerebellum. IP3R1 levels were decreased relative to cell-specific marker proteins. In tgHDCAG51n rats we found reduced IP3R1 levels in the cerebellum, but otherwise unchanged IP3R1 phosphorylation and protein levels. In BACHD and zQ175DNKI mice only age-dependent decline of IP3R1 was observed. CONCLUSION The level and phosphorylation of IP3R1 is reduced to a variable degree in the different HD models relative to control, indicating that earlier findings in more aggressive exon 1-truncated HD models may not be replicated in models with higher construct validity. Further analysis of possible coupling of reduced IP3R1 levels with development of neuropathological responses and cell-specific degeneration is warranted.
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Affiliation(s)
- Joakim Iver Post
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway.,Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Trygve B Leergaard
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Veronika Ratz
- Department for Experimental Therapy, Preclinical Experimental Centre, Friedrich-Alexander-University Erlangen-Nürnberg, Germany
| | - S Ivar Walaas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Stephan von Hörsten
- Department for Experimental Therapy, Preclinical Experimental Centre, Friedrich-Alexander-University Erlangen-Nürnberg, Germany
| | - Lise Sofie H Nissen-Meyer
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway.,Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Department of Immunology and Transfusion, Oslo University Hospital, Oslo, Norway
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3
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Ryanodine receptors contribute to the induction of ischemic tolerance. Brain Res Bull 2016; 122:45-53. [DOI: 10.1016/j.brainresbull.2016.02.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/14/2015] [Accepted: 02/24/2016] [Indexed: 11/21/2022]
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4
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Kopil CM, Vais H, Cheung KH, Siebert AP, Mak DOD, Foskett JK, Neumar RW. Calpain-cleaved type 1 inositol 1,4,5-trisphosphate receptor (InsP(3)R1) has InsP(3)-independent gating and disrupts intracellular Ca(2+) homeostasis. J Biol Chem 2011; 286:35998-36010. [PMID: 21859719 PMCID: PMC3195633 DOI: 10.1074/jbc.m111.254177] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 08/02/2011] [Indexed: 11/06/2022] Open
Abstract
The type 1 inositol 1,4,5-trisphosphate receptor (InsP(3)R1) is a ubiquitous intracellular Ca(2+) release channel that is vital to intracellular Ca(2+) signaling. InsP(3)R1 is a proteolytic target of calpain, which cleaves the channel to form a 95-kDa carboxyl-terminal fragment that includes the transmembrane domains, which contain the ion pore. However, the functional consequences of calpain proteolysis on channel behavior and Ca(2+) homeostasis are unknown. In the present study we have identified a unique calpain cleavage site in InsP(3)R1 and utilized a recombinant truncated form of the channel (capn-InsP(3)R1) corresponding to the stable, carboxyl-terminal fragment to examine the functional consequences of channel proteolysis. Single-channel recordings of capn-InsP(3)R1 revealed InsP(3)-independent gating and high open probability (P(o)) under optimal cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) conditions. However, some [Ca(2+)](i) regulation of the cleaved channel remained, with a lower P(o) in suboptimal and inhibitory [Ca(2+)](i). Expression of capn-InsP(3)R1 in N2a cells reduced the Ca(2+) content of ionomycin-releasable intracellular stores and decreased endoplasmic reticulum Ca(2+) loading compared with control cells expressing full-length InsP(3)R1. Using a cleavage-specific antibody, we identified calpain-cleaved InsP(3)R1 in selectively vulnerable cerebellar Purkinje neurons after in vivo cardiac arrest. These findings indicate that calpain proteolysis of InsP(3)R1 generates a dysregulated channel that disrupts cellular Ca(2+) homeostasis. Furthermore, our results demonstrate that calpain cleaves InsP(3)R1 in a clinically relevant injury model, suggesting that Ca(2+) leak through the proteolyzed channel may act as a feed-forward mechanism to enhance cell death.
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Affiliation(s)
- Catherine M Kopil
- Department of Emergency Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Horia Vais
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - King-Ho Cheung
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of Physiology, University of Hong Kong, Pok Fu Lam, Hong Kong, China
| | - Adam P Siebert
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Don-On Daniel Mak
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - J Kevin Foskett
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Robert W Neumar
- Department of Emergency Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
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5
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Mekahli D, Bultynck G, Parys JB, De Smedt H, Missiaen L. Endoplasmic-reticulum calcium depletion and disease. Cold Spring Harb Perspect Biol 2011; 3:a004317. [PMID: 21441595 PMCID: PMC3098671 DOI: 10.1101/cshperspect.a004317] [Citation(s) in RCA: 313] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The endoplasmic reticulum (ER) as an intracellular Ca(2+) store not only sets up cytosolic Ca(2+) signals, but, among other functions, also assembles and folds newly synthesized proteins. Alterations in ER homeostasis, including severe Ca(2+) depletion, are an upstream event in the pathophysiology of many diseases. On the one hand, insufficient release of activator Ca(2+) may no longer sustain essential cell functions. On the other hand, loss of luminal Ca(2+) causes ER stress and activates an unfolded protein response, which, depending on the duration and severity of the stress, can reestablish normal ER function or lead to cell death. We will review these various diseases by mainly focusing on the mechanisms that cause ER Ca(2+) depletion.
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Affiliation(s)
- Djalila Mekahli
- Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, KU Leuven Campus Gasthuisberg O&N I, Belgium
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6
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Bukowska A, Lendeckel U, Bode-Böger SM, Goette A. Physiologic and Pathophysiologic Role of Calpain: Implications for the Occurrence of Atrial Fibrillation. Cardiovasc Ther 2010; 30:e115-27. [DOI: 10.1111/j.1755-5922.2010.00245.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
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7
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Abstract
The calpain family of proteases is causally linked to postischemic neurodegeneration. However, the precise mechanisms by which calpains contribute to postischemic neuronal death have not been fully elucidated. This review outlines the key features of the calpain system, and the evidence for its causal role in postischemic neuronal pathology. Furthermore, the consequences of specific calpain substrate cleavage at various subcellular locations are explored. Calpain substrates within synapses, plasma membrane, endoplasmic reticulum, lysosomes, mitochondria, and the nucleus, as well as the overall effect of postischemic calpain activity on calcium regulation and cell death signaling are considered. Finally, potential pathways for calpain-mediated neurodegeneration are outlined in an effort to guide future studies aimed at understanding the downstream pathology of postischemic calpain activity and identifying optimal therapeutic strategies.
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Affiliation(s)
- Matthew B Bevers
- Department of Emergency Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-4283, USA
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8
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Tauskela JS, Morley P. On the role of Ca2+ in cerebral ischemic preconditioning. Cell Calcium 2005; 36:313-22. [PMID: 15261487 DOI: 10.1016/j.ceca.2004.02.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2004] [Accepted: 02/18/2004] [Indexed: 01/15/2023]
Abstract
Cerebral ischemic preconditioning (IPC) represents a potent endogenous method of inducing tolerance to otherwise lethal ischemia, both in in vivo and in vitro models. Investigation into the mechanism of this phenomenon has yet again transformed the way that neuroscientists view Ca2+. Generally viewed as an agent of neuronal death, particularly within an excitotoxic setting of cerebral ischemia, Ca2+ is now regarded as a key mediator of IPC. Classification of the role of Ca2+ in IPC defies simple description, but seems to possess a stimulatory role during the tolerance-inducing ischemia and an inhibitory or modulatory role during or following the second normally lethal ischemia.
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Affiliation(s)
- Joseph S Tauskela
- National Research Council, Institute for Biological Sciences, Montreal Road Campus, Building M-54, Ottawa, ON, Canada K1A 0R6.
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9
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Krepsova K, Micutkova L, Novotova M, Kubovcakova L, Kvetnansky R, Krizanova O. Repeated immobilization stress decreases mRNA and protein levels of the type 1 IP3 receptor in rat heart. Ann N Y Acad Sci 2004; 1018:339-44. [PMID: 15240388 DOI: 10.1196/annals.1296.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Stress is one of the major contributors to the development of cardiovascular disorders and psychiatric illnesses. Immobilization stress belongs to severe stressors and is known to activate several calcium transport systems. The aim of this work was to determine whether repeated immobilization stress changes mRNA and protein levels of the type 1 and 2 inositol-1,4,5-trisphosphate (IP(3)) receptors in cardiac tissue. Rats were immobilized for 7 days, 2 h daily. After repeated immobilization, increased numbers of collagen fibers were accumulated in the heart atria compared to hearts of the control group of rats. Gene expression was determined after reverse transcription and subsequent real-time polymerase chain reaction, using SYBR Green fluorescent dye. Protein levels were determined by Western blot and hybridization with the primary antibody against IP(3) receptors. Contrary to single immobilization, repeated immobilization decreased a gene expression of the type 1 and 2 IP(3) receptors, and also protein levels of the IP(3) receptors. Although the physiologic relevance of our observations remains to be elucidated, we propose that the decrease in IP(3) receptors may have an impact on the development of the pathophysiologic changes in the heart.
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MESH Headings
- Animals
- Base Sequence
- Blotting, Western
- Calcium Channels/genetics
- Calcium Channels/metabolism
- DNA Primers
- Immobilization
- Inositol 1,4,5-Trisphosphate Receptors
- Male
- Myocardium/metabolism
- Myocardium/ultrastructure
- Polymerase Chain Reaction
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Stress, Physiological/genetics
- Stress, Physiological/metabolism
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Affiliation(s)
- Katarina Krepsova
- D.Sc., Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34 Bratislava, Slovak Republic.
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10
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Krizanova O, Krepsova K, Micutkova L, Kvetnansky R. Inositol 1,4,5-Trisphosphate Receptors in the Heart Compared to Other Tissues Are Differently Modulated by Stress. Ann N Y Acad Sci 2004; 1018:310-4. [PMID: 15240383 DOI: 10.1196/annals.1296.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
IP(3) receptors are intracellular calcium channels, releasing calcium from the sarcoplasmic reticulum. In the heart, IP(3) receptors of type 1 and 2 were found. These receptors predominate in atria, although they occur also in ventricles, as determined by real-time PCR and Western blot analysis. Single-immobilization stress was found to increase mRNA and/or protein levels of types 1 and 2 IP(3) receptors in cardiac atria. However, in stellate ganglia, which innervate the heart, no changes in the mRNA of the type 1 IP(3) receptors were observed after single-immobilization stress. In adrenal medulla, a moderate decrease in both mRNA and protein levels of IP(3) receptors was observed after single-immobilization exposure. After repeated immobilization, mRNA and protein levels of types 1 and 2 IP(3) receptors decreased significantly in all tested tissues. Our results point to different processing of the single stress in different tissues, while repeated stress results in rapid and significant decrease of the IP(3) receptors.
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Affiliation(s)
- Olga Krizanova
- Institute of Molecular Physiology & Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34 Bratislava, Slovak Republic.
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11
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Micutkova L, Kvetnansky R, Krizanova O. Repeated immobilization stress reduces the gene expression of the type 1 and 2 IP3 receptors in stellate ganglia. Neurochem Int 2003; 43:557-61. [PMID: 12820984 DOI: 10.1016/s0197-0186(03)00066-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Inositol 1,4,5-trisphosphate (IP(3)) is one of the second messengers produced by phosphoinositid hydrolysis and triggers IP(3) receptor (IP(3)R) mediated calcium release from intracellular pools. To determine whether immobilization stress affects the gene expression and protein level of IP(3)R in stellate ganglia, animals were immobilized once for 2h and/or for 7 days, 2h daily. After decapitation, stellate ganglia were extirpated and the gene expression of IP(3) receptors was evaluated. Protein levels of IP(3) receptor were measured by Western blot analysis using the antibody against IP(3) receptor. In the present work, we clearly show that type 1 and 2 IP(3) receptors, but not the type 3 IP(3) receptor, are expressed in stellate ganglia. Both types, type 1 and 2 IP(3) receptors, are not significantly affected by single 2h immobilization stress on mRNA and protein level. However, gene expression of both these types is significantly reduced by repeated immobilization stress for 7 days, 2h daily. The IP(3) receptor protein is reduced as well. Physiological relevance of our observations remains to be elucidated.
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Affiliation(s)
- L Micutkova
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
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12
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Murray JN, Igwe OJ. Regulation of beta-amyloid precursor protein and inositol 1,4,5-trisphosphate receptor gene expression during differentiation of a human neuronal cell line. Prog Neuropsychopharmacol Biol Psychiatry 2003; 27:351-63. [PMID: 12691770 DOI: 10.1016/s0278-5846(02)00352-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Retinoic acid-induced differentiation of SH-SY5Y human neuroblastoma cells results in the development of extensive neurite processes as well as changes in cell body morphology toward a neuronal phenotype. The authors have examined concurrent regulation of beta-amyloid precursor protein (APP) and inositol 1,4,5-trisphosphate receptor (insP(3)R) gene expression in SY5Y cells during neuronal differentiation. Of the multiple APP mRNA transcripts expressed in this cell line, retinoic acid treatment significantly increased the expression of APP(695) transcript while the level of total APP remained unchanged. In the same time course, neuronal differentiation decreased the expression of insP(3)R at both the mRNA and protein levels. These findings demonstrate an inverse relationship between APP and insP(3)R gene expression during neuronal differentiation of SH-SY5Y cells and suggest a possible change in intracellular calcium homeostasis.
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Affiliation(s)
- John N Murray
- Division of Pharmacology, School of Pharmacy, University of Missouri-Kansas City, Medical School Building, Room M3-103, 2411 Holmes Street, Kansas City, MO 64108-2792, USA
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13
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Kocan J, Lencesova L, Kiss A, Ondrias K, Kvetnansky R, Krizanova O. Distribution of neuronal and non-neuronal spliced variants of type 1 IP(3)-receptor in rat hypothalamus and brain stem. Neurochem Int 2002; 41:65-70. [PMID: 11918973 DOI: 10.1016/s0197-0186(01)00135-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the nervous system, inositol 1,4,5-trisphosphate (IP(3)) is one of the second messengers produced by PI hydrolysis and triggers IP(3)-receptor (IP(3)R) mediated calcium release from intracellular pools. Throughout the brain, the type 1 IP(3)R is predominantly expressed and its mRNA is widely distributed. Alternative splicing of IP(3)R1 (SI and SII) occurs in two distinct regions. SI splicing in the middle of the ligand binding domain may alter the IP(3) binding activity, while SII splicing probably affects the protein kinase A phosphorylation sites and kinetics. Selective use of IP(3)-receptor subtypes may permit a tissue specific and developmentally specific expression of functionally distinct channels. The present work was focused on detection of the alternatively spliced mRNA of type 1 IP(3)-receptor in individual brain structures and nuclei. Using RT-PCR we detected neuronal (535bp) and non-neuronal (410bp) forms. We identified both spliced variants in the majority of brain structures, except in the cerebellum and medulla. In the cerebellum, the neuronal form of type 1 IP(3)R was found exclusively, while in the medulla, the non-neuronal form was much more abundant. Nevertheless, Western blot analysis and hybridization with specific antibody against IP(3)R revealed no qualitative, but only quantitative differences. Similarly, IP(3) dependent calcium release did not show any differences between the cerebellum and pons. These results demonstrate the distribution of alternatively spliced S2 variants of type 1 IP(3)R in selected brain structures and nuclei. The physiological relevance of these two forms remains to be elucidated by further studies.
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Affiliation(s)
- J Kocan
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34 Bratislava, Slovak Republic
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14
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Wrang ML, Møller F, Alsbo CW, Diemer NH. Changes in gene expression following induction of ischemic tolerance in rat brain: detection and verification. J Neurosci Res 2001; 65:54-8. [PMID: 11433429 DOI: 10.1002/jnr.1127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tolerance against ischemic insults can be elicited in the CA1 region of rat hippocampus by inducing a short ischemic period 2-3 days prior to the ischemic insult. To detect genes whose expression changes following induction of ischemic tolerance (IT), we applied a differential display technique called restriction fragment differential display-PCR (RFDD-PCR). RFDD-PCR displays the coding region of mRNA and allows detection of differentially expressed mRNA. Double-stranded cDNA generated using a T25V primer is digested by the endonuclease TaqI, and adapters are ligated onto the cDNA fragments. When amplifying the adapter-containing cDNA fragments under high-stringency conditions, reproducible PCR profiles are obtained. By comparing these profiles from naïve and ischemia-tolerant rat brains statistically, significant expression changes of 20 fragments were identified. To verify the observed changes, quantitative PCR and in situ hybridization were performed for three fragments representing proteins with quite different functions (GluR2-flop, SC1, and p68 RNA helicase). Quantitative PCR displayed the same degree of regulation as RFDD-PCR, but in situ hybridization did not display any regulation. As the applied PCR-based techniques detect only polyadenylated mRNA, whereas in situ hybridization detects both nonadenylated and adenylated mRNA, changes in the polyadenylation state of the mRNA, rather than inconsistent changes in the total amount of mRNA, probably explain this discrepancy. Thus, our results show that the expression of genes hitherto not related to IT changes with the induction of IT and that the degree of regulation displayed by RFDD-PCR can be verified by quantitative PCR.
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Affiliation(s)
- M L Wrang
- Laboratory of Neuropathology, Institute of Molecular Pathology, University of Copenhagen, and NeuroScience PharmaBiotech, Copenhagen, Denmark.
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15
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Poirier SN, Poitras M, Laflamme K, Guillemette G. Thiol-reactive agents biphasically regulate inositol 1,4,5-trisphosphate binding and Ca(2+) release activities in bovine adrenal cortex microsomes. Endocrinology 2001; 142:2614-21. [PMID: 11356712 DOI: 10.1210/endo.142.6.8195] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Within all endocrine cells, the inositol 1,4,5-trisphosphate (InsP(3)) receptor plays an important role in regulation of the intracellular Ca(2+) concentration. In the present study we showed that a single short-term treatment with either N-ethylmaleimide (known to decrease InsP(3) receptor activity) or thimerosal (known to increase InsP(3) receptor activity) caused time-dependent biphasic effects on the InsP(3) binding activity of bovine adrenal cortex microsomes. The early potentiating effect of thiol-reactive agents translated into a 2-fold increase in binding affinity and Ca(2+) release efficiency. The late dampening effect of thiol-reactive agents translated into a continuous reduction of the maximal binding capacity of the microsomes with a concomitant decrease in Ca(2+) release efficiency. Under these conditions, Western blot analyses demonstrated that the level of InsP(3) receptor protein was not modified. Sequential treatments with thimerosal and the reducing agent dithiothreitol showed that the InsP(3) receptor can readily oscillate between high and low affinity states that are related to its alkylation state. Our results suggest a common mode of action of thiol-reactive agents on the InsP(3) receptor. These results also support the contention that cellular mechanisms of thiol group modification could play important roles in regulation of the intracellular Ca(2+) concentration.
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Affiliation(s)
- S N Poirier
- Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Québec, Canada J1H 5N4
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