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Sade Y, Toker L, Kara NZ, Einat H, Rapoport S, Moechars D, Berry GT, Bersudsky Y, Agam G. IP3 accumulation and/or inositol depletion: two downstream lithium's effects that may mediate its behavioral and cellular changes. Transl Psychiatry 2016; 6:e968. [PMID: 27922641 PMCID: PMC5315558 DOI: 10.1038/tp.2016.217] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/17/2016] [Accepted: 09/12/2016] [Indexed: 12/12/2022] Open
Abstract
Lithium is the prototype mood stabilizer but its mechanism is still unresolved. Two hypotheses dominate-the consequences of lithium's inhibition of inositol monophosphatase at therapeutically relevant concentrations (the 'inositol depletion' hypothesis), and of glycogen-synthase kinase-3. To further elaborate the inositol depletion hypothesis that did not decisively determine whether inositol depletion per se, or phosphoinositols accumulation induces the beneficial effects, we utilized knockout mice of either of two inositol metabolism-related genes-IMPA1 or SMIT1, both mimic several lithium's behavioral and biochemical effects. We assessed in vivo, under non-agonist-stimulated conditions, 3H-inositol incorporation into brain phosphoinositols and phosphoinositides in wild-type, lithium-treated, IMPA1 and SMIT1 knockout mice. Lithium treatment increased frontal cortex and hippocampal phosphoinositols labeling by several fold, but decreased phosphoinositides labeling in the frontal cortex of the wild-type mice of the IMPA1 colony strain by ~50%. Inositol metabolites were differently affected by IMPA1 and SMIT1 knockout. Inositoltrisphosphate administered intracerebroventricularly affected bipolar-related behaviors and autophagy markers in a lithium-like manner. Namely, IP3 but not IP1 reduced the immobility time of wild-type mice in the forced swim test model of antidepressant action by 30%, an effect that was reversed by an antagonist of all three IP3 receptors; amphetamine-induced hyperlocomotion of wild-type mice (distance traveled) was 35% reduced by IP3 administration; IP3 administration increased hippocampal messenger RNA levels of Beclin-1 (required for autophagy execution) and hippocampal and frontal cortex protein levels ratio of Beclin-1/p62 by about threefold (p62 is degraded by autophagy). To conclude, lithium affects the phosphatidylinositol signaling system in two ways: depleting inositol, consequently decreasing phosphoinositides; elevating inositol monophosphate levels followed by phosphoinositols accumulation. Each or both may mediate lithium-induced behavior.
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Affiliation(s)
- Y Sade
- Department of Clinical Biochemistry and Pharmacology, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Psychiatry Research Unit, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Mental Health Center, Beer-Sheva, Israel
| | - L Toker
- Department of Psychiatry and Centre for High-Throughput Biology, University of British Columbia Vancouver, BC, Canada
| | - N Z Kara
- Department of Clinical Biochemistry and Pharmacology, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Psychiatry Research Unit, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel,School of Behavioral Sciences, Tel Aviv-Yaffo Academic College, Tel Aviv, Israel
| | - H Einat
- School of Behavioral Sciences, Tel Aviv-Yaffo Academic College, Tel Aviv, Israel
| | - S Rapoport
- Brain Physiology and Metabolism Section, Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, MD, USA
| | - D Moechars
- Johnson & Johnson Pharmaceutical Research and Development, Beerse, Belgium
| | - G T Berry
- Metabolism Program Division of Genetics, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - Y Bersudsky
- Psychiatry Research Unit, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Mental Health Center, Beer-Sheva, Israel
| | - G Agam
- Department of Clinical Biochemistry and Pharmacology, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Psychiatry Research Unit, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel,Mental Health Center, Beer-Sheva, Israel,Professor, , Department of Clinical Biochemistry and Pharmacology, Ben-Gurion University of the Negev or Psychiatry Research Unit, Ben-Gurion University of the Negev or Faculty of Health Sciences, Ben-Gurion University of the Negev or Mental Health Center, Beer-Sheva 84170, Israel. E-mail:
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Sardo P, Rizzo V, Friscia S, Carletti F, De Caro V, Scaturro AL, Giandalia G, Giannola LI, Ferraro G. Inhibitory effects of N-valproyl-l-tryptophan on high potassium, low calcium and low magnesium-induced CA1 hippocampal epileptiform bursting activity in rat brain slices. J Neural Transm (Vienna) 2012; 119:1249-59. [DOI: 10.1007/s00702-012-0814-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 04/20/2012] [Indexed: 11/30/2022]
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Chang P, Orabi B, Deranieh RM, Dham M, Hoeller O, Shimshoni JA, Yagen B, Bialer M, Greenberg ML, Walker MC, Williams RSB. The antiepileptic drug valproic acid and other medium-chain fatty acids acutely reduce phosphoinositide levels independently of inositol in Dictyostelium. Dis Model Mech 2012; 5:115-24. [PMID: 21876211 PMCID: PMC3255550 DOI: 10.1242/dmm.008029] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 07/14/2011] [Indexed: 12/11/2022] Open
Abstract
Valproic acid (VPA) is the most widely prescribed epilepsy treatment worldwide, but its mechanism of action remains unclear. Our previous work identified a previously unknown effect of VPA in reducing phosphoinositide production in the simple model Dictyostelium followed by the transfer of data to a mammalian synaptic release model. In our current study, we show that the reduction in phosphoinositide [PtdInsP (also known as PIP) and PtdInsP(2) (also known as PIP(2))] production caused by VPA is acute and dose dependent, and that this effect occurs independently of phosphatidylinositol 3-kinase (PI3K) activity, inositol recycling and inositol synthesis. In characterising the structural requirements for this effect, we also identify a family of medium-chain fatty acids that show increased efficacy compared with VPA. Within the group of active compounds is a little-studied group previously associated with seizure control, and analysis of two of these compounds (nonanoic acid and 4-methyloctanoic acid) shows around a threefold enhanced potency compared with VPA for protection in an in vitro acute rat seizure model. Together, our data show that VPA and a newly identified group of medium-chain fatty acids reduce phosphoinositide levels independently of inositol regulation, and suggest the reinvestigation of these compounds as treatments for epilepsy.
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Affiliation(s)
- Pishan Chang
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Benoit Orabi
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Rania M. Deranieh
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Manik Dham
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Oliver Hoeller
- Department of Cellular and Molecular Pharmacology and the Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94158, USA
| | - Jakob A. Shimshoni
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Boris Yagen
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Meir Bialer
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Miriam L. Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Matthew C. Walker
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Robin S. B. Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
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Azab AN, Agam G, Kaplanski J, Delbar V, Greenberg ML. Inositol depletion: a good or bad outcome of valproate treatment? FUTURE NEUROLOGY 2008. [DOI: 10.2217/14796708.3.3.275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bipolar affective disorder is a severe and chronic disabling illness affecting 1.5% of the general population. Lithium, valproate and other mood stabilizers are used to treat bipolar disorder; however, these are ineffective for, and not tolerated by, a significant percentage of patients, underscoring the urgent need for better medications. Although not universally accepted, the inositol-depletion hypothesis is one of the main hypotheses suggested to explain the therapeutic mechanism of mood-stabilizing drugs. This paper reviews the relevance of the inositol-depletion hypothesis, paying special attention to the inhibition of inositol de novo synthesis by valproate. It also discusses inositol supplementation as a treatment strategy for multiple neurological disorders, including prophylactic use against valproate-induced neural tube defects.
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Affiliation(s)
- Abed N Azab
- Ben-Gurion University of the Negev, School for Community Health Professions, Faculty of Health Sciences, PO Box 653, Beer-Sheva 84105, Israel
| | - Galila Agam
- Ben-Gurion University of the Negev, Psychiatry Research Unit & Department of Clinical Biochemistry, Faculty of Health Sciences, PO Box 4600, Beer-Sheva 84170, Israel
| | - Jacob Kaplanski
- Ben-Gurion University of the Negev, Department of Clinical Pharmacology, Faculty of Health Sciences, PO Box 653, Beer-Sheva 84105, Israel
| | - Vered Delbar
- Ben-Gurion University of the Negev, School for Community Health Professions, Faculty of Health Sciences, PO Box 653, Beer-Sheva 84105, Israel
| | - Miriam L Greenberg
- Wayne State University, Department of Biological Sciences, Detroit, MI 48202, USA
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McGrath BM, McKay R, Dave S, Seres P, Weljie AM, Slupsky CM, Hanstock CC, Greenshaw AJ, Silverstone PH. Acute dextro-amphetamine administration does not alter brain myo-inositol levels in humans and animals: MRS investigations at 3 and 18.8 T. Neurosci Res 2008; 61:351-9. [PMID: 18508145 DOI: 10.1016/j.neures.2008.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 04/05/2008] [Accepted: 04/09/2008] [Indexed: 11/24/2022]
Abstract
The pathophysiological underpinnings of bipolar disorder are not fully understood. However, they may be due in part to changes in the phosphatidylinositol second messenger system (PI-cycle) generally, or changes in myo-inositol concentrations more specifically. Dextro-amphetamine has been used as a model for mania in several human studies as it causes similar subjective and physiological symptoms. We wanted to determine if dextro-amphetamine altered myo-inositol concentrations in vivo as it would clearly define a mechanism linking putative changes in the PI-cycle to the subjective psychological changes seen with dextro-amphetamine administration. Fifteen healthy human volunteers received a baseline scan, followed by second scan 75 min after receiving a 25 mg oral dose of dextro-amphetamine. Stimulated echo proton magnetic resonance spectroscopy (MRS) scans were preformed at 3.0 Tesla (T) in the dorsal medial prefrontal cortex (DMPFC). Metabolite data were adjusted for tissue composition and analyzed using LCModel. Twelve adult male rats were treated acutely with a 5-mg/kg intraperitoneal dose of dextro-amphetamine. After 1 h rats were decapitated and the brains were rapidly removed and frozen until dissection. Rat brains were dissected into frontal, temporal, and occipital cortical areas, as well as hippocampus. Tissue was analyzed using a Varian 18.8 T spectrometer. Metabolites were identified and quantified using Chenomx Profiler software. The main finding in the present study was that myo-inositol concentrations in the DMPFC of human volunteers and in the four rat brain regions were not altered by acute dextro-amphetamine. While it remains possible that the PI-cycle may be involved in the pathophysiology of bipolar disorder, it is not likely that the subjective and physiological of dextro-amphetamine are mediated, directly or indirectly, via alternations in myo-inositol concentrations.
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Affiliation(s)
- Brent M McGrath
- Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada T6G 2B7.
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