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Nakamura T, Nakajima K, Kobayashi Y, Itohara S, Kasahara T, Tsuboi T, Kato T. Functional and behavioral effects of de novo mutations in calcium-related genes in patients with bipolar disorder. Hum Mol Genet 2021; 30:1851-1862. [PMID: 34100076 PMCID: PMC8444452 DOI: 10.1093/hmg/ddab152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 05/30/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
Bipolar disorder is a common mental illness occurring in approximately 1% of individuals and exhibits lifetime prevalence. Although genetic factors are known to contribute to this disorder, the genetic architecture has not yet been completely clarified. Our initial trio-based exome sequencing study of bipolar disorder showed enrichment of de novo, loss-of-function (LOF) or protein-altering mutations in a combined group with bipolar I and schizoaffective disorders, and the identified de novo mutations were enriched in calcium-related genes. These findings suggested a role for de novo mutations in bipolar disorder. The validity of these statistical associations can be demonstrated if the functional impact of the mutations on cellular function and behavior are identified. In this study, we focused on two de novo LOF mutations in calcium-related genes, EHD1 and MACF1, found in patients with bipolar disorder. We first showed that the EHD1 mutation resulted in a truncated protein with diminished effect on neurite outgrowth and inhibited endocytosis. Next, we used CRISPR/Cas9 to establish two knock-in mouse lines to model the in vivo effects of these mutations. We performed behavioral screening using IntelliCage and long-term wheel running analysis. Ehd1 mutant mice showed higher activity in the light phase. Macf1 mutant mice showed diminished attention and persistence to rewards. These behavioral alterations were similar to the phenotypes in previously proposed animal models of bipolar disorder. These findings endorse the possible role of de novo mutations as a component of the genetic architecture of bipolar disorder which was suggested by the statistical evidence.
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Affiliation(s)
- Takumi Nakamura
- Department of Psychiatry & Behavioral Science, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Saitama, Japan
| | - Kazuo Nakajima
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Saitama, Japan
| | - Yuki Kobayashi
- Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Saitama, Japan
| | - Shigeyoshi Itohara
- Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Saitama, Japan
| | - Takaoki Kasahara
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Saitama, Japan
| | - Takashi Tsuboi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Tadafumi Kato
- Department of Psychiatry & Behavioral Science, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Saitama, Japan
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2
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Gonzalez S. The Role of Mitonuclear Incompatibility in Bipolar Disorder Susceptibility and Resilience Against Environmental Stressors. Front Genet 2021; 12:636294. [PMID: 33815470 PMCID: PMC8010675 DOI: 10.3389/fgene.2021.636294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/22/2021] [Indexed: 12/23/2022] Open
Abstract
It has been postulated that mitochondrial dysfunction has a significant role in the underlying pathophysiology of bipolar disorder (BD). Mitochondrial functioning plays an important role in regulating synaptic transmission, brain function, and cognition. Neuronal activity is energy dependent and neurons are particularly sensitive to changes in bioenergetic fluctuations, suggesting that mitochondria regulate fundamental aspects of brain function. Vigorous evidence supports the role of mitochondrial dysfunction in the etiology of BD, including dysregulated oxidative phosphorylation, general decrease of energy, altered brain bioenergetics, co-morbidity with mitochondrial disorders, and association with genetic variants in mitochondrial DNA (mtDNA) or nuclear-encoded mitochondrial genes. Despite these advances, the underlying etiology of mitochondrial dysfunction in BD is unclear. A plausible evolutionary explanation is that mitochondrial-nuclear (mitonuclear) incompatibility leads to a desynchronization of machinery required for efficient electron transport and cellular energy production. Approximately 1,200 genes, encoded from both nuclear and mitochondrial genomes, are essential for mitochondrial function. Studies suggest that mitochondrial and nuclear genomes co-evolve, and the coordinated expression of these interacting gene products are essential for optimal organism function. Incompatibilities between mtDNA and nuclear-encoded mitochondrial genes results in inefficiency in electron flow down the respiratory chain, differential oxidative phosphorylation efficiency, increased release of free radicals, altered intracellular Ca2+ signaling, and reduction of catalytic sites and ATP production. This review explores the role of mitonuclear incompatibility in BD susceptibility and resilience against environmental stressors.
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Affiliation(s)
- Suzanne Gonzalez
- Department of Psychiatry and Behavioral Health, Department of Pharmacology, Penn State College of Medicine, Hershey, PA, United States
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3
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Bagge EK, Fujimori-Tonou N, Kubota-Sakashita M, Kasahara T, Kato T. Unbiased PCR-free spatio-temporal mapping of the mtDNA mutation spectrum reveals brain region-specific responses to replication instability. BMC Biol 2020; 18:150. [PMID: 33097039 PMCID: PMC7585204 DOI: 10.1186/s12915-020-00890-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/06/2020] [Indexed: 12/24/2022] Open
Abstract
Background The accumulation of mtDNA mutations in different tissues from various mouse models has been widely studied especially in the context of mtDNA mutation-driven ageing but has been confounded by the inherent limitations of the most widely used approaches. By implementing a method to sequence mtDNA without PCR amplification prior to library preparation, we map the full unbiased mtDNA mutation spectrum across six distinct brain regions from mice. Results We demonstrate that ageing-induced levels of mtDNA mutations (single nucleotide variants and deletions) reach stable levels at 50 weeks of age but can be further elevated specifically in the cortex, nucleus accumbens (NAc), and paraventricular thalamic nucleus (PVT) by expression of a proof-reading-deficient mitochondrial DNA polymerase, PolgD181A. The increase in single nucleotide variants increases the fraction of shared SNVs as well as their frequency, while characteristics of deletions remain largely unaffected. In addition, PolgD181A also induces an ageing-dependent accumulation of non-coding control-region multimers in NAc and PVT, a feature that appears almost non-existent in wild-type mice. Conclusions Our data provide a novel view of the spatio-temporal accumulation of mtDNA mutations using very limited tissue input. The differential response of brain regions to a state of replication instability provides insight into a possible heterogenic mitochondrial landscape across the brain that may be involved in the ageing phenotype and mitochondria-associated disorders.
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Affiliation(s)
- Emilie Kristine Bagge
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Noriko Fujimori-Tonou
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan.,Current address: Support Unit for Bio-Material Analysis, Research Resources Division, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Mie Kubota-Sakashita
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Takaoki Kasahara
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan.,Current address: Career Development Program, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan. .,Department of Psychiatry and Behavioral Science, Juntendo University, Graduate School of Medicine, Hongo 2-1-1, Bunkyo, Tokyo 113-8421, Japan.
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4
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Reply to "Correspondence to Ant1 mutant mice bridge the mitochondrial and serotonergic dysfunctions in bipolar disorder". Mol Psychiatry 2020; 25:2205-2206. [PMID: 30353171 DOI: 10.1038/s41380-018-0279-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 09/11/2018] [Indexed: 11/08/2022]
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5
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Kasahara T, Kubota-Sakashita M, Nagatsuka Y, Hirabayashi Y, Hanasaka T, Tohyama K, Kato T. Cardiolipin is essential for early embryonic viability and mitochondrial integrity of neurons in mammals. FASEB J 2019; 34:1465-1480. [PMID: 31914590 DOI: 10.1096/fj.201901598r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 10/08/2019] [Accepted: 10/23/2019] [Indexed: 11/11/2022]
Abstract
Cardiolipin (CL) is a hallmark phospholipid of mitochondria and plays a significant role in maintaining the mitochondrial structure and functions. Despite the physiological importance of CL, mutant organisms, yeast, Arabidopsis, C elegans, and Drosophila, which lack CL synthase (Crls1) gene and consequently are deprived of CL, are viable. Here we report conditional Crls1-deficient mice using targeted insertion of loxP sequences flanking the functional domain of CRLS1 enzyme. Homozygous null mutant mice exhibited early embryonic lethality at the peri-implantation stage. We generated neuron-specific Crls1 knockout (cKO) mice by crossing with Camk2α-Cre mice. Neuronal loss and gliosis were gradually manifested in the forebrains, where CL levels were significantly decreased. In the surviving neurons, malformed mitochondria with bubble-like or onion-like inner membrane structures were observed. We showed decreased supercomplex assembly and reduced enzymatic activities of electron transport chain complexes in the forebrain of cKO mice, resulting in affected mitochondrial calcium dynamics, a slower rate of Ca2+ uptake and a smaller calcium retention capacity. These observations clearly demonstrate indispensable roles of CL as well as of Crls1 gene in mammals.
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Affiliation(s)
- Takaoki Kasahara
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako-shi, Japan
| | - Mie Kubota-Sakashita
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako-shi, Japan
| | - Yasuko Nagatsuka
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Itabashi-ku, Japan
| | - Yoshio Hirabayashi
- Cellular Informatics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Japan.,Institute for Environmental and Gender Specific Medicine, Juntendo University, Graduate School of Medicine, Urayasu-shi, Japan
| | - Tomohito Hanasaka
- Department of Physiology School of Dentistry, The Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University, Yahaba-cho, Japan
| | - Koujiro Tohyama
- Department of Physiology School of Dentistry, The Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University, Yahaba-cho, Japan
| | - Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako-shi, Japan
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6
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Limanaqi F, Biagioni F, Ryskalin L, Busceti CL, Fornai F. Molecular Mechanisms Linking ALS/FTD and Psychiatric Disorders, the Potential Effects of Lithium. Front Cell Neurosci 2019; 13:450. [PMID: 31680867 PMCID: PMC6797817 DOI: 10.3389/fncel.2019.00450] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 09/20/2019] [Indexed: 12/12/2022] Open
Abstract
Altered proteostasis, endoplasmic reticulum (ER) stress, abnormal unfolded protein response (UPR), mitochondrial dysfunction and autophagy impairment are interconnected events, which contribute to the pathogenesis of amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). In recent years, the mood stabilizer lithium was shown to potentially modify ALS/FTD beyond mood disorder-related pathology. The effects of lithium are significant in ALS patients carrying genetic variations in the UNC13 presynaptic protein, which occur in ALS/FTD and psychiatric disorders as well. In the brain, lithium modulates a number of biochemical pathways involved in synaptic plasticity, proteostasis, and neuronal survival. By targeting UPR-related events, namely ER stress, excitotoxicity and autophagy dysfunction, lithium produces plastic effects. These are likely to relate to neuroprotection, which was postulated for mood and motor neuron disorders. In the present manuscript, we try to identify and discuss potential mechanisms through which lithium copes concomitantly with ER stress, UPR and autophagy dysfunctions related to UNC13 synaptic alterations and aberrant RNA and protein processing. This may serve as a paradigm to provide novel insights into the neurobiology of ALS/FTD featuring early psychiatric disturbances.
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Affiliation(s)
- Fiona Limanaqi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - Larisa Ryskalin
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | - Francesco Fornai
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.,IRCCS Neuromed, Pozzilli, Italy
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7
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Kato T. Current understanding of bipolar disorder: Toward integration of biological basis and treatment strategies. Psychiatry Clin Neurosci 2019; 73:526-540. [PMID: 31021488 DOI: 10.1111/pcn.12852] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 04/19/2019] [Accepted: 04/22/2019] [Indexed: 12/18/2022]
Abstract
Biological studies of bipolar disorder initially focused on the mechanism of action for antidepressants and antipsychotic drugs, and the roles of monoamines (e.g., serotonin, dopamine) have been extensively studied. Thereafter, based on the mechanism of action of lithium, intracellular signal transduction systems, including inositol metabolism and intracellular calcium signaling, have drawn attention. Involvement of intracellular calcium signaling has been supported by genetics and cellular studies. Elucidation of the neural circuits affected by calcium signaling abnormalities is critical, and our previous study suggested a role of the paraventricular thalamic nucleus. The genetic vulnerability of mitochondria causes calcium dysregulation and results in the hyperexcitability of serotonergic neurons, which are suggested to be susceptible to oxidative stress. Efficacy of anticonvulsants, animal studies of candidate genes, and studies using induced pluripotent stem cell-derived neurons have suggested a relation between bipolar disorder and the hyperexcitability of neurons. Recent genetic findings suggest the roles of polyunsaturated acids. At the systems level, social rhythm therapy targets circadian rhythm abnormalities, and cognitive behavioral therapy may target emotion/cognition (E/C) imbalance. In the future, pharmacological and psychosocial treatments may be combined and optimized based on the biological basis of each patient, which will realize individualized treatment.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Japan
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8
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Vercesi AE, Castilho RF, Kowaltowski AJ, de Oliveira HCF, de Souza-Pinto NC, Figueira TR, Busanello ENB. Mitochondrial calcium transport and the redox nature of the calcium-induced membrane permeability transition. Free Radic Biol Med 2018; 129:1-24. [PMID: 30172747 DOI: 10.1016/j.freeradbiomed.2018.08.034] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/16/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022]
Abstract
Mitochondria possess a Ca2+ transport system composed of separate Ca2+ influx and efflux pathways. Intramitochondrial Ca2+ concentrations regulate oxidative phosphorylation, required for cell function and survival, and mitochondrial redox balance, that participates in a myriad of signaling and damaging pathways. The interaction between Ca2+ accumulation and redox imbalance regulates opening and closing of a highly regulated inner membrane pore, the membrane permeability transition pore (PTP). In this review, we discuss the regulation of the PTP by mitochondrial oxidants, reactive nitrogen species, and the interactions between these species and other PTP inducers. In addition, we discuss the involvement of mitochondrial redox imbalance and PTP in metabolic conditions such as atherogenesis, diabetes, obesity and in mtDNA stability.
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Affiliation(s)
- Anibal E Vercesi
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil.
| | - Roger F Castilho
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Helena C F de Oliveira
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, SP, Brazil
| | - Nadja C de Souza-Pinto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Tiago R Figueira
- Escola de Educação Física e Esporte de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Estela N B Busanello
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil
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9
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Riveros ME, Retamal MA. Are Polyunsaturated Fatty Acids Implicated in Histaminergic Dysregulation in Bipolar Disorder?: AN HYPOTHESIS. Front Physiol 2018; 9:693. [PMID: 29946266 PMCID: PMC6005883 DOI: 10.3389/fphys.2018.00693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 05/18/2018] [Indexed: 12/28/2022] Open
Abstract
Bipolar disorder (BD) is an extremely disabling psychiatric disease, characterized by alternate states of mania (or hypomania) and depression with euthymic states in between. Currently, patients receive pharmacological treatment with mood stabilizers, antipsychotics, and antidepressants. Unfortunately, not all patients respond well to this type of treatment. Bipolar patients are also more prone to heart and metabolic diseases as well as a higher risk of suicide compared to the healthy population. For a correct brain function is indispensable a right protein and lipids (e.g., fatty acids) balance. In particular, the amount of fatty acids in the brain corresponds to a 50–70% of the dry weight. It has been reported that in specific brain regions of BD patients there is a reduction in the content of unsaturated n-3 fatty acids. Accordingly, a diet rich in n-3 fatty acids has beneficial effects in BD patients, while their absence or high levels of saturated fatty acids in the diet are correlated to the risk of developing the disease. On the other hand, the histamine system is likely to be involved in the pathophysiology of several psychiatric diseases such as BD. Histamine is a neuromodulator involved in arousal, motivation, and energy balance; drugs acting on the histamine receptor H3 have shown potential as antidepressants and antipsychotics. The histaminergic system as other neurotransmission systems can be altered by fatty acid membrane composition. The purpose of this review is to explore how polyunsaturated fatty acids content alterations are related to the histaminergic system modulation and their impact in BD pathophysiology.
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Affiliation(s)
- María E Riveros
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile.,Center of Applied Ecology and Sustainability, Santiago, Chile
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile.,Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, United States
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10
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Kato TM, Kubota-Sakashita M, Fujimori-Tonou N, Saitow F, Fuke S, Masuda A, Itohara S, Suzuki H, Kato T. Ant1 mutant mice bridge the mitochondrial and serotonergic dysfunctions in bipolar disorder. Mol Psychiatry 2018; 23:2039-2049. [PMID: 29892051 PMCID: PMC6250678 DOI: 10.1038/s41380-018-0074-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/26/2018] [Accepted: 03/26/2018] [Indexed: 01/30/2023]
Abstract
Although mitochondrial and serotonergic dysfunctions have been implicated in the etiology of bipolar disorder (BD), the relationship between these unrelated pathways has not been elucidated. A family of BD and chronic progressive external ophthalmoplegia (CPEO) caused by a mutation of the mitochondrial adenine nucleotide translocator 1 (ANT1, SLC25A4) implicated that ANT1 mutations confer a risk of BD. Here, we sequenced ANT1 in 324 probands of NIMH bipolar disorder pedigrees and identified two BD patients carrying heterozygous loss-of-function mutations. Behavioral analysis of brain specific Ant1 heterozygous conditional knockout (cKO) mice using lntelliCage showed a selective diminution in delay discounting. Delay discounting is the choice of smaller but immediate reward than larger but delayed reward and an index of impulsivity. Diminution of delay discounting suggests an increase in serotonergic activity. This finding was replicated by a 5-choice serial reaction time test. An anatomical screen showed accumulation of COX (cytochrome c oxidase) negative cells in dorsal raphe. Dorsal raphe neurons in the heterozygous cKO showed hyperexcitability, along with enhanced serotonin turnover in the nucleus accumbens and upregulation of Maob in dorsal raphe. These findings altogether suggest that mitochondrial dysfunction as the genetic risk of BD may cause vulnerability to BD by altering serotonergic neurotransmission.
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Affiliation(s)
- Tomoaki M. Kato
- grid.474690.8Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan ,0000 0004 0372 2033grid.258799.8Present Address: Department of Fundamental Cell Technology, Center for iPS Cell Research and Application, Kyoto University, Kyoto, Japan
| | - Mie Kubota-Sakashita
- grid.474690.8Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Noriko Fujimori-Tonou
- grid.474690.8Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Fumihito Saitow
- 0000 0001 2173 8328grid.410821.eDepartment of Pharmacology, Nippon Medical School, Tokyo, Japan
| | - Satoshi Fuke
- grid.474690.8Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Akira Masuda
- grid.474690.8Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Shigeyoshi Itohara
- grid.474690.8Laboratory for Behavioral Genetics, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Hidenori Suzuki
- 0000 0001 2173 8328grid.410821.eDepartment of Pharmacology, Nippon Medical School, Tokyo, Japan
| | - Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Center for Brain Science, Wako, Saitama, Japan.
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11
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Kato T. Neurobiological basis of bipolar disorder: Mitochondrial dysfunction hypothesis and beyond. Schizophr Res 2017; 187:62-66. [PMID: 27839913 DOI: 10.1016/j.schres.2016.10.037] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/24/2016] [Accepted: 10/27/2016] [Indexed: 02/07/2023]
Abstract
Bipolar disorder is one of two major psychotic disorders together with schizophrenia and causes severe psychosocial disturbance. Lack of adequate animal models hampers development of new mood stabilizers. We proposed a mitochondrial dysfunction hypothesis and have been studying the neurobiology of bipolar disorder based on this hypothesis. We showed that deletions of mitochondrial DNA (ΔmtDNA) play a pathophysiological role at least in some patients with bipolar disorder possibly by affecting intracellular calcium regulation. Mutant polymerase γ transgenic mice that accumulate ΔmtDNA in the brain showed recurrent spontaneous depression-like episodes which were prevented by a serotonin-selective reuptake inhibitor and worsened by lithium withdrawal. The animal model would be useful to develop new mood stabilizers.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamic of Mental Disorders, RIKEN Brain Science Institute, Japan.
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12
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Plant N. Can a systems approach produce a better understanding of mood disorders? Biochim Biophys Acta Gen Subj 2016; 1861:3335-3344. [PMID: 27565355 DOI: 10.1016/j.bbagen.2016.08.016] [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: 02/17/2016] [Revised: 07/29/2016] [Accepted: 08/22/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND One in twenty-five people suffer from a mood disorder. Current treatments are sub-optimal with poor patient response and uncertain modes-of-action. There is thus a need to better understand underlying mechanisms that determine mood, and how these go wrong in affective disorders. Systems biology approaches have yielded important biological discoveries for other complex diseases such as cancer, and their potential in affective disorders will be reviewed. SCOPE OF REVIEW This review will provide a general background to affective disorders, plus an outline of experimental and computational systems biology. The current application of these approaches in understanding affective disorders will be considered, and future recommendations made. MAJOR CONCLUSIONS Experimental systems biology has been applied to the study of affective disorders, especially at the genome and transcriptomic levels. However, data generation has been slowed by a lack of human tissue or suitable animal models. At present, computational systems biology has only be applied to understanding affective disorders on a few occasions. These studies provide sufficient novel biological insight to motivate further use of computational biology in this field. GENERAL SIGNIFICANCE In common with many complex diseases much time and money has been spent on the generation of large-scale experimental datasets. The next step is to use the emerging computational approaches, predominantly developed in the field of oncology, to leverage the most biological insight from these datasets. This will lead to the critical breakthroughs required for more effective diagnosis, stratification and treatment of affective disorders.
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Affiliation(s)
- Nick Plant
- School of Bioscience and Medicine, Faculty of Health and Medical Science, University of Surrey, Guildford GU2 7XH, UK.
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Zayats T, Johansson S, Haavik J. Expanding the toolbox of ADHD genetics. How can we make sense of parent of origin effects in ADHD and related behavioral phenotypes? Behav Brain Funct 2015; 11:33. [PMID: 26475699 PMCID: PMC4609130 DOI: 10.1186/s12993-015-0078-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/07/2015] [Indexed: 01/09/2023] Open
Abstract
Genome-wide association (GWA) studies have shown that many different genetic variants cumulatively contribute to the risk of psychiatric disorders. It has also been demonstrated that various parent-of-origin effects (POE) may differentially influence the risk of these disorders. Together, these observations have provided important new possibilities to uncover the genetic underpinnings of such complex phenotypes. As POE so far have received little attention in neuropsychiatric disorders, there is still much progress to be made. Here, we mainly focus on the new and emerging role of POE in attention-deficit hyperactivity disorder (ADHD). We review the current evidence that POE play an imperative role in vulnerability to ADHD and related disorders. We also discuss how POE can be assessed using statistical genetics tools, expanding the resources of modern psychiatric genetics. We propose that better comprehension and inspection of POE may offer new insight into the molecular basis of ADHD and related phenotypes, as well as the potential for preventive and therapeutic interventions.
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Affiliation(s)
- Tetyana Zayats
- Department of Biomedicine, K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.
| | - Stefan Johansson
- Department of Clinical Science, K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway. .,Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway.
| | - Jan Haavik
- Department of Biomedicine, K.G. Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, Bergen, Norway. .,Division of Psychiatry, Haukeland University Hospital, Bergen, Norway.
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14
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Toker L, Agam G. Mitochondrial dysfunction in psychiatric morbidity: current evidence and therapeutic prospects. Neuropsychiatr Dis Treat 2015; 11:2441-7. [PMID: 26442764 PMCID: PMC4590577 DOI: 10.2147/ndt.s70346] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cumulating evidence for the involvement of mitochondrial dysfunction in psychiatric disorders leaves little to no doubt regarding the involvement of this pathology in mood disorders. However, mitochondrial abnormalities are also observed in a wide range of disorders spanning from cancer and diabetes to various neurodegenerative and neurodevelopmental disorders such as Parkinson's, Alzheimer's, Huntington's, autism, and amyotrophic lateral sclerosis. The apparent lack of specificity questions the role of mitochondrial dysfunction in psychiatric disorders, in general, and in mood disorders, in particular. Is mitochondrial dysfunction a general phenomenon, simplistically rendering brain cells to be more vulnerable to a variety of disease-specific perturbations? Or is it an epiphenomenon induced by various disease-specific factors? Or possibly, the severity and the anatomical region of the dysfunction are the ones responsible for the distinct features of the disorders. Whichever of the aforementioned ones, if any, is correct, "mitochondrial dysfunction" became more of a cliché than a therapeutic target. In this review, we summarize current studies supporting the involvement of mitochondrial dysfunction in different psychiatric disorders. We address the question of specificity and causality of the different findings and provide an alternative explanation for some of the aforementioned questions.
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Affiliation(s)
- Lilach Toker
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Galila Agam
- Department of Clinical Biochemistry and Pharmacology, Ben-Gurion University of the Negev, Beer-Sheva, Israel ; Mental Health Center, Beer-Sheva, Israel
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15
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Perier C, Bender A, García-Arumí E, Melià MJ, Bové J, Laub C, Klopstock T, Elstner M, Mounsey RB, Teismann P, Prolla T, Andreu AL, Vila M. Accumulation of mitochondrial DNA deletions within dopaminergic neurons triggers neuroprotective mechanisms. ACTA ACUST UNITED AC 2013; 136:2369-78. [PMID: 23884809 DOI: 10.1093/brain/awt196] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Acquired alterations in mitochondrial DNA are believed to play a pathogenic role in Parkinson's disease. In particular, accumulation of mitochondrial DNA deletions has been observed in substantia nigra pars compacta dopaminergic neurons from patients with Parkinson's disease and aged individuals. Also, mutations in mitochondrial DNA polymerase gamma result in multiple mitochondrial DNA deletions that can be associated with levodopa-responsive parkinsonism and severe substantia nigra pars compacta dopaminergic neurodegeneration. However, whether mitochondrial DNA deletions play a causative role in the demise of dopaminergic neurons remains unknown. Here we assessed the potential pathogenic effects of mitochondrial DNA deletions on the dopaminergic nigrostriatal system by using mutant mice possessing a proofreading-deficient form of mitochondrial DNA polymerase gamma (POLGD257A), which results in a time-dependent accumulation of mitochondrial DNA deletions in several tissues, including the brain. In these animals, we assessed the occurrence of mitochondrial DNA deletions within individual substantia nigra pars compacta dopaminergic neurons, by laser capture microdissection and quantitative real-time polymerase chain reaction, and determined the potential deleterious effects of such mitochondrial DNA alterations on mitochondrial function and dopaminergic neuronal integrity, by cytochrome c oxidase histochemistry and quantitative morphology. Nigral dopaminergic neurons from POLGD257A mice accumulate mitochondrial DNA deletions to a similar extent (∼40-60%) as patients with Parkinson's disease and aged individuals. Despite such high levels of mitochondrial DNA deletions, the majority of substantia nigra pars compacta dopaminergic neurons from these animals did not exhibit mitochondrial dysfunction or degeneration. Only a few individual substantia nigra pars compacta neurons appeared as cytochrome c oxidase-negative, which exhibited higher levels of mitochondrial DNA deletions than cytochrome c oxidase-positive cells (60.38±3.92% versus 45.18±2.83%). Survival of dopaminergic neurons in POLGD257A mice was associated with increased mitochondrial DNA copy number, enhanced mitochondrial cristae network, improved mitochondrial respiration, decreased exacerbation of mitochondria-derived reactive oxygen species, greater striatal dopamine levels and resistance to parkinsonian mitochondrial neurotoxins. These results indicate that primary accumulation of mitochondrial DNA deletions within substantia nigra pars compacta dopaminergic neurons, at an extent similar to that observed in patients with Parkinson's disease, do not kill dopaminergic neurons but trigger neuroprotective compensatory mechanisms at a mitochondrial level that may account for the high pathogenic threshold of mitochondrial DNA deletions in these cells.
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Affiliation(s)
- Celine Perier
- Vall d'Hebron Research Institute and Centre for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Barcelona, Spain.
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16
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Shi XF, Kondo DG, Sung YH, Hellem TL, Fiedler KK, Jeong EK, Huber RS, Renshaw PF. Frontal lobe bioenergetic metabolism in depressed adolescents with bipolar disorder: a phosphorus-31 magnetic resonance spectroscopy study. Bipolar Disord 2012; 14:607-17. [PMID: 22816670 PMCID: PMC4651435 DOI: 10.1111/j.1399-5618.2012.01040.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To compare the concentrations of high-energy phosphorus metabolites associated with mitochondrial function in the frontal lobe of depressed adolescents with bipolar disorder (BD) and healthy controls (HC). METHODS We used in vivo phosphorus-31 magnetic resonance spectroscopy ((31) P-MRS) at 3 Tesla to measure phosphocreatine (PCr), beta-nucleoside triphosphate (β-NTP), inorganic phosphate (Pi), and other neurometabolites in the frontal lobe of eight unmedicated and six medicated adolescents with bipolar depression and 24 adolescent HCs. RESULTS Analysis of covariance, including age as a covariate, revealed differences in PCr (p=0.037), Pi (p=0.017), and PCr/Pi (p=0.002) between participant groups. Percentage neurochemical differences were calculated with respect to mean metabolite concentrations in the HC group. Post-hoc Tukey-Kramer analysis showed that unmedicated BD participants had decreased Pi compared with both HC (17%; p=0.038) and medicated BD (24%; p=0.022). The unmedicated BD group had increased PCr compared with medicated BD (11%; p=0.032). The PCr/Pi ratio was increased in unmedicated BD compared with HC (24%; p=0.013) and with medicated BD (39%; p=0.002). No differences in β-NTP or pH were observed. CONCLUSIONS Our results support the view that frontal lobe mitochondrial function is altered in adolescent BD and may have implications for the use of Pi as a biomarker. These findings join volumetric studies of the amygdala, and proton MRS studies of n-acetyl aspartate in pointing to potential differences in neurobiology between pediatric and adult BD.
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Affiliation(s)
- Xian-Feng Shi
- The Brain Institute, University of Utah, 383 Colorow Drive, Salt Lake City, UT 84108, USA.
| | - Douglas G Kondo
- The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT, USA,Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, USA,VISN 19 Mental Illness Research, Education and Clinical Center (MIRECC), Department of Veterans Affairs Medical Center, Salt Lake City, UT, USA
| | - Young-Hoon Sung
- The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT, USA,Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Tracy L Hellem
- The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Kristen K Fiedler
- The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Eun-Kee Jeong
- Department of Radiology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Rebekah S Huber
- The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Perry F Renshaw
- The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT, USA,Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, USA,VISN 19 Mental Illness Research, Education and Clinical Center (MIRECC), Department of Veterans Affairs Medical Center, Salt Lake City, UT, USA
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Abstract
Major psychiatric illnesses such as mood disorders and schizophrenia are chronic, recurrent mental illnesses that affect the lives of millions of individuals. Although these disorders have traditionally been viewed as 'neurochemical diseases', it is now clear that they are associated with impairments of synaptic plasticity and cellular resilience. Although most patients with these disorders do not have classic mitochondrial disorders, there is a growing body of evidence to suggest that impaired mitochondrial function may affect key cellular processes, thereby altering synaptic functioning and contributing to the atrophic changes that underlie the deteriorating long-term course of these illnesses. Enhancing mitochondrial function could represent an important avenue for the development of novel therapeutics and also presents an opportunity for a potentially more efficient drug-development process.
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Kato T, Hayashi-Takagi A, Toyota T, Yoshikawa T, Iwamoto K. Gene expression analysis in lymphoblastoid cells as a potential biomarker of bipolar disorder. J Hum Genet 2011; 56:779-83. [DOI: 10.1038/jhg.2011.101] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Abstract
The mitochondrial dysfunction hypothesis was proposed to integrate various findings in bipolar disorder (BPD). This hypothesis is supported by possible roles of maternal inheritance, comorbidity with mitochondrial diseases, the mechanism of action of mood stabilizers, magnetic resonance spectroscopy, mitochondrial DNA mutations, gene expression analysis, and phenotypes of animal models. Mitochondrial dysfunction is not specific to BPD but is common to many neurodegenerative disorders. It would be reasonable to assume that neurons regulating mood are progressively impaired during the course of BPD. Further studies are needed to clarify which neural systems are impaired by mitochondrial dysfunction in BPD.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Hirosawa 2-1, Wako, Saitama, 351-0198, Japan,
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20
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Kubota M, Kasahara T, Iwamoto K, Komori A, Ishiwata M, Miyauchi T, Kato T. Therapeutic implications of down-regulation of cyclophilin D in bipolar disorder. Int J Neuropsychopharmacol 2010; 13:1355-68. [PMID: 20392297 DOI: 10.1017/s1461145710000362] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We previously reported that neuron-specific mutant Polg1 (mitochondrial DNA polymerase) transgenic (Tg) mice exhibited bipolar disorder (BD)-like phenotypes such as periodic activity change and altered circadian rhythm. In this study, we re-evaluated two datasets resulting from DNA microarray analysis to estimate a biological pathway associated with the disorder. The gene lists were derived from the comparison between post-mortem brains of BD patients and control subjects, and from the comparison between the brains of Tg and wild-type mice. Gene ontology analysis showed that 16 categories overlapped in the altered gene expression profiles of BD patients and the mouse model. In the brains of Tg mice, 33 genes showed similar changes in the frontal cortex and hippocampus compared to wild-type mice. Among the 33 genes, SFPQ and PPIF were differentially expressed in post-mortem brains of BD patients compared to control subjects. The only gene consistently down-regulated in both patients and the mouse model was PPIF, which encodes cyclophilin D (CypD), a component of the mitochondrial permeability transition pore. A blood-brain barrier-permeable CypD inhibitor significantly improved the abnormal behaviour of Tg mice at 40 mg/kg.d. These findings collectively suggest that CypD is a promising target for a new drug for BD.
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Affiliation(s)
- Mie Kubota
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Wako, Saitama, Japan
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21
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Curley JP, Mashoodh R. Parent-of-origin and trans-generational germline influences on behavioral development: the interacting roles of mothers, fathers, and grandparents. Dev Psychobiol 2010; 52:312-30. [PMID: 20373326 DOI: 10.1002/dev.20430] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Mothers and fathers do not contribute equally to the development of their offspring. In addition to the differential investment of mothers versus fathers in the rearing of offspring, there are also a number of germline factors that are transmitted unequally from one parent or the other that contribute significantly to offspring development. This article shall review four major sources of such parent-of-origin effects. Firstly, there is increasing evidence that genes inherited on the sex chromosomes including the nonpseudoautosomal part of the Y chromosome that is only inherited from fathers to sons, contribute to brain development and behavior independently of the organizing effects of sex hormones. Secondly, recent work has demonstrated that mitochondrial DNA that is primarily inherited only from mothers may play a much greater than anticipated role in neurobehavioral development. Thirdly, there exists a class of genes known as imprinted genes that are epigenetically silenced when passed on in a parent-of-origin specific manner and have been shown to regulate brain development and a variety of behaviors. Finally, there is converging evidence from several disciplines that environmental variations experienced by mothers and fathers may lead to plasticity in the development and behavior of offspring and that this phenotypic inheritance can be solely transmitted through the germline. Mechanistically, this may be achieved through altered programming within germ cells of the epigenetic status of particular genes such as retrotransposons and imprinted genes or potentially through altered expression of RNAs within gametes.
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Affiliation(s)
- J P Curley
- Department of Psychology, Columbia University, Room 406, Schermerhorn Hall, 1190 Amsterdam Avenue, New York, NY 10027, USA.
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22
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Evidence for selective microRNAs and their effectors as common long-term targets for the actions of mood stabilizers. Neuropsychopharmacology 2009; 34:1395-405. [PMID: 18704095 PMCID: PMC2669666 DOI: 10.1038/npp.2008.131] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
MicroRNAs (miRNAs) regulate messenger RNA (mRNA) translation in a sequence-specific manner and are emerging as critical regulators of central nervous system plasticity. We found hippocampal miRNA level changes following chronic treatment with mood stabilizers (lithium and valproate (VPA)). Several of these miRNAs were then confirmed by quantitative PCR: let-7b, let-7c, miR-128a, miR-24a, miR-30c, miR-34a, miR-221, and miR-144. The predicted effectors of these miRNAs are involved in neurite outgrowth, neurogenesis, and signaling of PTEN, ERK, and Wnt/beta-catenin pathways. Interestingly, several of these effector-coding genes are also genetic risk candidates for bipolar disorder. We provide evidence that treatment with mood stabilizers increases these potential susceptibility genes in vivo: dipeptidyl-peptidase 10, metabotropic glutamate receptor 7 (GRM7), and thyroid hormone receptor, beta. Treatment of primary cultures with lithium- or VPA-lowered levels of miR-34a and elevated levels of GRM7, a predicted effector of miR-34a. Conversely, miR-34a precursor treatment lowered GRM7 levels and treatment with a miR-34a inhibitor enhanced GRM7 levels. These data confirm that endogenous miR-34a regulates GRM7 levels and supports the notion that miR-34a contributes to the effects of lithium and VPA on GRM7. These findings are the first to demonstrate that miRNAs and their predicted effectors are targets for the action of psychotherapeutic drugs.
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23
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Calcium regulation of mitochondria motility and morphology. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:1363-73. [PMID: 19138660 DOI: 10.1016/j.bbabio.2008.12.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 12/10/2008] [Accepted: 12/10/2008] [Indexed: 12/21/2022]
Abstract
In the Fifties, electron microscopy studies on neuronal cells showed that mitochondria typically cluster at synaptic terminals, thereby introducing the concept that proper mitochondria trafficking and partitioning inside the cell could provide functional support to the execution of key physiological processes. Today, the notion that a central event in the life of every eukaryotic cell is to configure, maintain, and reorganize the mitochondrial network at sites of high energy demand in response to environmental and cellular cues is well established, and the challenge ahead is to define the underlying molecular mechanisms and regulatory pathways. Recent pioneering studies have further contributed to place mitochondria at the center of the cell biology by showing that the machinery governing remodeling of mitochondria shape and structure regulates the functional output of the organelle as the powerhouse of the cell, the gateway to programmed cell death, and the platform for Ca(2+) signaling. Thus, a raising issue is to identify the cues integrating mitochondria trafficking and dynamics into cell physiology and metabolism. Given the versatile function of calcium as a second messenger and of the role of mitochondria as a major calcium store, evidences are emerging linking Ca(2+) transients to the modulation of mitochondrial activities. This review focuses on calcium as a switch controlling mitochondria motility and morphology in steady state, stressed, and pathological conditions.
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Vempati UD, Torraco A, Moraes CT. Mouse models of oxidative phosphorylation dysfunction and disease. Methods 2008; 46:241-7. [PMID: 18848991 PMCID: PMC2652743 DOI: 10.1016/j.ymeth.2008.09.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 08/28/2008] [Accepted: 09/12/2008] [Indexed: 11/23/2022] Open
Abstract
Oxidative phosphorylation (OXPHOS) deficiency results in a number of human diseases, affecting at least one in 5000 of the general population. Altering the function of genes by mutations are central to our understanding their function. Prior to the development of gene targeting, this approach was limited to rare spontaneous mutations that resulted in a phenotype. Since its discovery, targeted mutagenesis of the mouse germline has proved to be a powerful approach to understand the in vivo function of genes. Gene targeting has yielded remarkable understanding of the role of several gene products in the OXPHOS system. We provide a "tool box" of mouse models with OXPHOS defects that could be used to answer diverse scientific questions.
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Affiliation(s)
| | | | - Carlos T. Moraes
- Department of Neurology, University of Miami, USA
- Department of Cell Biology & Anatomy, University of Miami, USA
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25
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Kato T. Molecular neurobiology of bipolar disorder: a disease of 'mood-stabilizing neurons'? Trends Neurosci 2008; 31:495-503. [PMID: 18774185 DOI: 10.1016/j.tins.2008.07.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 07/30/2008] [Accepted: 07/30/2008] [Indexed: 01/07/2023]
Abstract
Although the role of a genetic factor is established in bipolar disorder, causative genes or robust genetic risk factors have not been identified. Increased incidence of subcortical hyperintensity, altered calcium levels in cells derived from patients and neuroprotective effects of mood stabilizers suggest vulnerability or impaired resilience of neurons in bipolar disorder. Mitochondrial dysfunction or impaired endoplasmic reticulum stress response is suggested to play a role in the neurons' vulnerability. Progressive loss or dysfunction of 'mood-stabilizing neurons' might account for the characteristic course of the illness. The important next step in the neurobiological study of bipolar disorder is identification of the neural systems that are responsible for this disorder.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
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26
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Kato T. Role of mitochondrial DNA in calcium signaling abnormality in bipolar disorder. Cell Calcium 2008; 44:92-102. [PMID: 18177933 DOI: 10.1016/j.ceca.2007.11.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Revised: 11/21/2007] [Accepted: 11/22/2007] [Indexed: 11/23/2022]
Abstract
Altered intracellular calcium levels are a consistent finding in studies of bipolar disorder, and recent studies point to the role of mitochondrial dysfunction, leading to the possibility that mitochondrial calcium dysregulation is involved in the pathophysiology of the disease. Although the mitochondrion is a key organelle for calcium accumulation, initial calcium signaling studies in bipolar disorder did not focus on the role of mitochondria. Later, neuroimaging and molecular genetic studies suggested the possibility that altered mitochondrial calcium regulation due to mitochondrial DNA (mtDNA) polymorphisms/mutations might be involved in the pathophysiology of bipolar disorder. Recent studies show that certain mtDNA polymorphisms alter mitochondrial calcium levels. Mutant mtDNA polymerase (Polg) transgenic mice carrying mtDNA mutations in forebrain cells show an increased calcium uptake rate in isolated mitochondria. This was found to be mediated by downregulation of cyclophilin D, a component of the mitochondrial permeability transition pore. In addition, agonist-stimulated calcium response is attenuated in hippocampal neurons of these transgenic mice. The finding that mtDNA polymorphisms and mutations affect mitochondrial calcium regulation supports the idea that mitochondrial calcium dysregulation may be involved in the pathophysiology of bipolar disorder. In this review, the history and recent findings of studies elucidating the role of mitochondrial calcium signaling in bipolar disorder are summarized.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Hirosawa 2-1, Wako, Saitama, Japan.
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27
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Fuke S, Kametani M, Kato T. Quantitative analysis of the 4977-bp common deletion of mitochondrial DNA in postmortem frontal cortex from patients with bipolar disorder and schizophrenia. Neurosci Lett 2008; 439:173-7. [DOI: 10.1016/j.neulet.2008.05.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 04/04/2008] [Accepted: 05/06/2008] [Indexed: 01/10/2023]
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28
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Yamasue H, Kakiuchi C, Tochigi M, Inoue H, Suga M, Abe O, Yamada H, Sasaki T, Rogers MA, Aoki S, Kato T, Kasai K. Association between mitochondrial DNA 10398A>G polymorphism and the volume of amygdala. GENES BRAIN AND BEHAVIOR 2008; 7:698-704. [PMID: 18518927 DOI: 10.1111/j.1601-183x.2008.00408.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Mitochondrial calcium regulation plays a number of important roles in neurons. Mitochondrial DNA (mtDNA) is highly polymorphic, and its interindividual variation is associated with various neuropsychiatric diseases and mental functions. An mtDNA polymorphism, 10398A>G, was reported to affect mitochondrial calcium regulation. Volume of hippocampus and amygdala is reportedly associated with various mental disorders and mental functions and is regarded as an endophenotype of mental disorders. The present study investigated the relationship between the mtDNA 10398A>G polymorphism and the volume of hippocampus and amygdala in 118 right-handed healthy subjects. The brain morphometry using magnetic resonance images employed both manual tracing volumetry in the native space and voxel-based morphometry (VBM) in the spatially normalized space. Amygdala volume was found to be significantly larger in healthy subjects with 10398A than in those with 10398G by manual tracing, which was confirmed by the VBM. Brain volumes in the other gray matter regions and all white matter regions showed no significant differences associated with the polymorphism. These provocative findings might provide a clue to the complex relationship between mtDNA, brain structure and mental disorders.
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Affiliation(s)
- H Yamasue
- Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
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Kasahara T, Kubota M, Miyauchi T, Ishiwata M, Kato T. A marked effect of electroconvulsive stimulation on behavioral aberration of mice with neuron-specific mitochondrial DNA defects. PLoS One 2008; 3:e1877. [PMID: 18365022 PMCID: PMC2267493 DOI: 10.1371/journal.pone.0001877] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Accepted: 02/22/2008] [Indexed: 01/16/2023] Open
Abstract
We developed transgenic (Tg) mice modeling an autosomally inherited mitochondrial disease, chronic progressive external ophthalmoplegia, patients with which sometimes have comorbid mood disorders. The mutant animals exhibited bipolar disorder-like phenotypes, such as a distorted day–night rhythm and a robust activity change with a period of 4–5 days, and the behavioral abnormalities were improved by lithium. In this study, we tested the effect of electroconvulsive stimulation (ECS) on the behavioral abnormalities of the model. Electroconvulsive therapy, which has long been used in clinical practice, provides fast-acting relief to depressive patients and drug-resistant patients. We performed long-term recordings of wheel-running activity of Tg and non-Tg mice. While recording, we administrated a train of ECS to mice, six times over two weeks or three times over a week. The treatment ameliorated the distorted day–night rhythm within three times of ECS, but it had no effect on the activity change with a period of 4–5 days in the female mice. To study the mechanism of the action, we investigated whether ECS could alter the circadian phase but found no influence on the circadian clock system. The potent and fast-acting efficacy of ECS in the mutant mice supports the predictive validity of the mice as a model of bipolar disorder. This model will be useful in developing a safe and effective alternative to lithium or electroconvulsive therapy.
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Affiliation(s)
- Takaoki Kasahara
- Laboratory for Molecular Dynamics of Mental Disorders, Brain Science Institute, RIKEN, Wako-shi, Saitama, Japan.
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30
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Kato T, Kubota M, Kasahara T. Animal models of bipolar disorder. Neurosci Biobehav Rev 2007; 31:832-42. [PMID: 17466374 DOI: 10.1016/j.neubiorev.2007.03.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 03/06/2007] [Accepted: 03/13/2007] [Indexed: 12/31/2022]
Abstract
Animal models of human diseases should meet three sets of criteria: construct validity, face validity, and predictive validity. To date, several putative animal models of bipolar disorder have been reported. They are classified into various categories: pharmacological models, nutritional models, environmental models, and genetic models. None of them, however, totally fulfills the three validity criteria, and thus may not be useful for drug development. Mounting evidence suggests that mitochondrial dysfunction has a role in bipolar disorder. To test whether accumulation of mtDNA deletions in the brain can cause bipolar disorder, we generated transgenic mice with neuron-specific expression of mutant Polg (D181A). These mice showed altered diurnal activity rhythm and periodic activity change associated with the estrous cycle. These phenotypes were worsened by administration of a tricyclic antidepressant, but improved after lithium treatment. This mouse model of bipolar disorder potentially fulfills the three validity criteria, and therefore might be used for future drug development studies.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Hirosawa 2-1, Wako, Saitama 351-0198, Japan.
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