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Omidsalar AA, McCullough CG, Xu L, Boedijono S, Gerke D, Webb MG, Manojlovic Z, Sequeira A, Lew MF, Santorelli M, Serrano GE, Beach TG, Limon A, Vawter MP, Hjelm BE. Common mitochondrial deletions in RNA-Seq: evaluation of bulk, single-cell, and spatial transcriptomic datasets. Commun Biol 2024; 7:200. [PMID: 38368460 PMCID: PMC10874445 DOI: 10.1038/s42003-024-05877-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 01/31/2024] [Indexed: 02/19/2024] Open
Abstract
Common mitochondrial DNA (mtDNA) deletions are large structural variants in the mitochondrial genome that accumulate in metabolically active tissues with age and have been investigated in various diseases. We applied the Splice-Break2 pipeline (designed for high-throughput quantification of mtDNA deletions) to human RNA-Seq datasets and describe the methodological considerations for evaluating common deletions in bulk, single-cell, and spatial transcriptomics datasets. A robust evaluation of 1570 samples from 14 RNA-Seq studies showed: (i) the abundance of some common deletions detected in PCR-amplified mtDNA correlates with levels observed in RNA-Seq data; (ii) RNA-Seq library preparation method has a strong effect on deletion detection; (iii) deletions had a significant, positive correlation with age in brain and muscle; (iv) deletions were enriched in cortical grey matter, specifically in layers 3 and 5; and (v) brain regions with dopaminergic neurons (i.e., substantia nigra, ventral tegmental area, and caudate nucleus) had remarkable enrichment of common mtDNA deletions.
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Affiliation(s)
- Audrey A Omidsalar
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Carmel G McCullough
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Lili Xu
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Stanley Boedijono
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Daniel Gerke
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Michelle G Webb
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Zarko Manojlovic
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Adolfo Sequeira
- Department of Psychiatry and Human Behavior, University of California - Irvine (UCI) School of Medicine, Irvine, CA, USA
| | - Mark F Lew
- Department of Neurology, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Marco Santorelli
- Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Geidy E Serrano
- Banner Sun Health Research Institute (BSHRI), Sun City, AZ, USA
| | - Thomas G Beach
- Banner Sun Health Research Institute (BSHRI), Sun City, AZ, USA
| | - Agenor Limon
- Mitchell Center for Neurodegenerative Diseases, Department of Neurology, School of Medicine, University of Texas Medical Branch, Galveston, TX, USA
| | - Marquis P Vawter
- Department of Psychiatry and Human Behavior, University of California - Irvine (UCI) School of Medicine, Irvine, CA, USA
| | - Brooke E Hjelm
- Department of Translational Genomics, Keck School of Medicine of USC, Los Angeles, CA, USA.
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Hjelm BE, Ramiro C, Rollins BL, Omidsalar AA, Gerke DS, Das SC, Sequeira A, Morgan L, Schatzberg AF, Barchas JD, Lee FS, Myers RM, Watson SJ, Akil H, Bunney WE, Vawter MP. Large Common Mitochondrial DNA Deletions Are Associated with a Mitochondrial SNP T14798C Near the 3' Breakpoints. Complex Psychiatry 2023; 8:90-98. [PMID: 36778651 PMCID: PMC9909249 DOI: 10.1159/000528051] [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: 05/02/2022] [Accepted: 10/19/2022] [Indexed: 11/16/2022] Open
Abstract
Introduction Large somatic deletions of mitochondrial DNA (mtDNA) accumulate with aging in metabolically active tissues such as the brain. We have cataloged the breakpoints and frequencies of large mtDNA deletions in the human brain. Methods We quantified 112 high-frequency mtDNA somatic deletions across four human brain regions with the Splice-Break2 pipeline. In addition, we utilized PLINK/Seq to test the association of mitochondrial genotypes with the abundance of these high-frequency mtDNA deletions. A conservative p value threshold of 5E-08 was used to find the significant loci. Results One mtDNA SNP (T14798C) was significantly associated with mtDNA deletions in two brain regions, the dorsolateral prefrontal cortex (DLPFC) and the superior temporal gyrus. Since the DLPFC showed the most robust association between T14798C and two deletion breakpoints (7816-14807 and 5462-14807), this association was tested in the DLPFC of a replication sample and validated the first results. Incorporating the C allele at 14,798 bp increased the perfect/imperfect length of the repeat at the 3' breakpoint of the two associated deletions. Conclusion This is the first study to identify the association of mtDNA SNP with large mtDNA deletions in the human brain. The T14798C allele located in the MT-CYB gene is a common polymorphism that occurs in several mitochondrial haplogroups. We hypothesize that the T14798C association with two deletions occurs by extending the repeat length around the 3' deletion breakpoints. This simple mechanism suggests that mtDNA SNPs can affect the mitochondrial genome structure, especially in brain where high levels of reactive oxygen species lead to deletion accumulation with aging.
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Affiliation(s)
- Brooke E. Hjelm
- Department of Translational Genomics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Christian Ramiro
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA
| | - Brandi L. Rollins
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA
| | - Audrey A. Omidsalar
- Department of Translational Genomics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Daniel S. Gerke
- Department of Translational Genomics, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Sujan C. Das
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA
| | - Adolfo Sequeira
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA
| | - Ling Morgan
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA
| | - Alan F. Schatzberg
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California, USA
| | - Jack D. Barchas
- Department of Psychiatry, Weill Cornell Medical College, Ithaca, New York, USA
| | - Francis S. Lee
- Department of Psychiatry, Weill Cornell Medical College, Ithaca, New York, USA
| | - Richard M. Myers
- HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Stanley J. Watson
- The Michigan Neuroscience Institute (MNI), University of Michigan, Ann Arbor, Michigan, USA
| | - Huda Akil
- The Michigan Neuroscience Institute (MNI), University of Michigan, Ann Arbor, Michigan, USA
| | - William E. Bunney
- Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA
| | - Marquis P. Vawter
- Functional Genomics Laboratory, Department of Psychiatry and Human Behavior, University of California, Irvine, California, USA,*Marquis P. Vawter,
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Das SC, Hjelm BE, Rollins BL, Sequeira A, Morgan L, Omidsalar AA, Schatzberg AF, Barchas JD, Lee FS, Myers RM, Watson SJ, Akil H, Bunney WE, Vawter MP. Mitochondria DNA copy number, mitochondria DNA total somatic deletions, Complex I activity, synapse number, and synaptic mitochondria number are altered in schizophrenia and bipolar disorder. Transl Psychiatry 2022; 12:353. [PMID: 36042222 PMCID: PMC9427957 DOI: 10.1038/s41398-022-02127-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 11/15/2022] Open
Abstract
Mitochondrial dysfunction is a neurobiological phenomenon implicated in the pathophysiology of schizophrenia and bipolar disorder that can synergistically affect synaptic neurotransmission. We hypothesized that schizophrenia and bipolar disorder share molecular alterations at the mitochondrial and synaptic levels. Mitochondria DNA (mtDNA) copy number (CN), mtDNA common deletion (CD), mtDNA total deletion, complex I activity, synapse number, and synaptic mitochondria number were studied in the postmortem human dorsolateral prefrontal cortex (DLPFC), superior temporal gyrus (STG), primary visual cortex (V1), and nucleus accumbens (NAc) of controls (CON), and subjects with schizophrenia (SZ), and bipolar disorder (BD). The results showed (i) the mtDNA CN is significantly higher in DLPFC of both SZ and BD, decreased in the STG of BD, and unaltered in V1 and NAc of both SZ and BD; (ii) the mtDNA CD is significantly higher in DLPFC of BD while unaltered in STG, V1, and NAc of both SZ and BD; (iii) The total deletion burden is significantly higher in DLPFC in both SZ and BD while unaltered in STG, V1, and NAc of SZ and BD; (iv) Complex I activity is significantly lower in DLPFC of both SZ and BD, which is driven by the presence of medications, with no alteration in STG, V1, and NAc. In addition, complex I protein concentration, by ELISA, was decreased across three cortical regions of SZ and BD subjects; (v) The number of synapses is decreased in DLPFC of both SZ and BD, while the synaptic mitochondria number was significantly lower in female SZ and female BD compared to female controls. Overall, these findings will pave the way to understand better the pathophysiology of schizophrenia and bipolar disorder for therapeutic interventions.
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Affiliation(s)
- Sujan C. Das
- grid.266093.80000 0001 0668 7243Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA USA
| | - Brooke E. Hjelm
- grid.42505.360000 0001 2156 6853Department of Translational Genomics, Keck School of Medicine, University of Southern California, Health Sciences Campus, Los Angeles, CA USA
| | - Brandi L. Rollins
- grid.266093.80000 0001 0668 7243Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA USA
| | - Adolfo Sequeira
- grid.266093.80000 0001 0668 7243Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA USA
| | - Ling Morgan
- grid.266093.80000 0001 0668 7243Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA USA
| | - Audrey A. Omidsalar
- grid.42505.360000 0001 2156 6853Department of Translational Genomics, Keck School of Medicine, University of Southern California, Health Sciences Campus, Los Angeles, CA USA
| | - Alan F. Schatzberg
- grid.168010.e0000000419368956Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA USA
| | - Jack D. Barchas
- grid.5386.8000000041936877XDepartment of Psychiatry, Weill Cornell Medical College, Ithaca, NJ USA
| | - Francis S. Lee
- grid.5386.8000000041936877XDepartment of Psychiatry, Weill Cornell Medical College, Ithaca, NJ USA
| | - Richard M. Myers
- grid.417691.c0000 0004 0408 3720HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806 USA
| | - Stanley J. Watson
- grid.214458.e0000000086837370The Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI USA
| | - Huda Akil
- grid.214458.e0000000086837370The Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI USA
| | - William E. Bunney
- grid.266093.80000 0001 0668 7243Department of Psychiatry & Human Behavior, University of California, Irvine, CA USA
| | - Marquis P. Vawter
- grid.266093.80000 0001 0668 7243Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA USA
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Valiente-Pallejà A, Tortajada J, Bulduk BK, Vilella E, Garrabou G, Muntané G, Martorell L. Comprehensive summary of mitochondrial DNA alterations in the postmortem human brain: A systematic review. EBioMedicine 2022; 76:103815. [PMID: 35085849 PMCID: PMC8790490 DOI: 10.1016/j.ebiom.2022.103815] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 12/24/2021] [Accepted: 01/05/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mitochondrial DNA (mtDNA) encodes 37 genes necessary for synthesizing 13 essential subunits of the oxidative phosphorylation system. mtDNA alterations are known to cause mitochondrial disease (MitD), a clinically heterogeneous group of disorders that often present with neuropsychiatric symptoms. Understanding the nature and frequency of mtDNA alterations in health and disease could be a cornerstone in disentangling the relationship between biochemical findings and clinical symptoms of brain disorders. This systematic review aimed to summarize the mtDNA alterations in human brain tissue reported to date that have implications for further research on the pathophysiological significance of mtDNA alterations in brain functioning. METHODS We searched the PubMed and Embase databases using distinct terms related to postmortem human brain and mtDNA up to June 10, 2021. Reports were eligible if they were empirical studies analysing mtDNA in postmortem human brains. FINDINGS A total of 158 of 637 studies fulfilled the inclusion criteria and were clustered into the following groups: MitD (48 entries), neurological diseases (NeuD, 55 entries), psychiatric diseases (PsyD, 15 entries), a miscellaneous group with controls and other clinical diseases (5 entries), ageing (20 entries), and technical issues (5 entries). Ten entries were ascribed to more than one group. Pathogenic single nucleotide variants (pSNVs), both homo- or heteroplasmic variants, have been widely reported in MitD, with heteroplasmy levels varying among brain regions; however, pSNVs are rarer in NeuD, PsyD and ageing. A lower mtDNA copy number (CN) in disease was described in most, but not all, of the identified studies. mtDNA deletions were identified in individuals in the four clinical categories and ageing. Notably, brain samples showed significantly more mtDNA deletions and at higher heteroplasmy percentages than blood samples, and several of the deletions present in the brain were not detected in the blood. Finally, mtDNA heteroplasmy, mtDNA CN and the deletion levels varied depending on the brain region studied. INTERPRETATION mtDNA alterations are well known to affect human tissues, including the brain. In general, we found that studies of MitD, NeuD, PsyD, and ageing were highly variable in terms of the type of disease or ageing process investigated, number of screened individuals, studied brain regions and technology used. In NeuD and PsyD, no particular type of mtDNA alteration could be unequivocally assigned to any specific disease or diagnostic group. However, the presence of mtDNA deletions and mtDNA CN variation imply a role for mtDNA in NeuD and PsyD. Heteroplasmy levels and threshold effects, affected brain regions, and mitotic segregation patterns of mtDNA alterations may be involved in the complex inheritance of NeuD and PsyD and in the ageing process. Therefore, more information is needed regarding the type of mtDNA alteration, the affected brain regions, the heteroplasmy levels, and their relationship with clinical phenotypes and the ageing process. FUNDING Hospital Universitari Institut Pere Mata; Institut d'Investigació Sanitària Pere Virgili; Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación (PI18/00514).
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Affiliation(s)
- Alba Valiente-Pallejà
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Juan Tortajada
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Bengisu K Bulduk
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Elisabet Vilella
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain
| | - Glòria Garrabou
- Laboratory of Muscle Research and Mitochondrial Function, Department of Internal Medicine-Hospital Clínic of Barcelona (HCB); Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); Faculty of Medicine and Health Sciences, Universitat de Barcelona (UB), 08036 Barcelona, Catalonia, Spain; Biomedical Network Research Centre on Rare Diseases (CIBERER), 28029 Madrid, Spain
| | - Gerard Muntané
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain; Institute of Evolutionary Biology (IBE), Universitat Pompeu Fabra (UPF), 08003 Barcelona, Catalonia, Spain
| | - Lourdes Martorell
- Research Department, Hospital Universitari Institut Pere Mata (HUIPM); Institut d'Investigació Sanitària Pere Virgili (IISPV); Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), 43201 Reus, Catalonia, Spain; Biomedical Network Research Centre on Mental Health (CIBERSAM), 28029 Madrid, Spain.
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Roberts RC. Mitochondrial dysfunction in schizophrenia: With a focus on postmortem studies. Mitochondrion 2021; 56:91-101. [PMID: 33221354 PMCID: PMC7810242 DOI: 10.1016/j.mito.2020.11.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/23/2020] [Accepted: 11/11/2020] [Indexed: 12/13/2022]
Abstract
Among the many brain abnormalities in schizophrenia are those related to mitochondrial functions such as oxidative stress, energy metabolism and synaptic efficacy. The aim of this paper is to provide a brief review of mitochondrial structure and function and then to present abnormalities in mitochondria in postmortem brain in schizophrenia with a focus on anatomy. Deficits in expression of various mitochondrial genes have been found in multiple schizophrenia cohorts. Decreased activity of complexes I and IV are prominent as well as abnormal levels of individual subunits that comprise the complexes of the electron transport chain. Ultrastructural studies have shown layer, input and cell specific decreases in mitochondria. In cortex, there are fewer mitochondria in axon terminals, neuronal somata of pyramidal neurons and oligodendrocytes in both grey and white matter. In the caudate and putamen mitochondrial number is linked with symptoms and symptom severity. While there is a decrease in the number of mitochondria in astrocytes, mitochondria are smaller in oligodendrocytes. In the nucleus accumbens and substantia nigra, mitochondria are similar in density, size and structural integrity in schizophrenia compared to controls. Mitochondrial production of ATP and calcium buffering are essential in maintaining synaptic strength and abnormalities in these processes could lead to decreased metabolism and defective synaptic activity. Abnormalities in mitochondria in oligodendrocytes might contribute to myelin pathology and underlie dysconnectivity in the brain. In schizophrenia, mitochondria are affected differentially depending on the brain region, cell type in which they reside, subcellular location, treatment status, treatment response and predominant symptoms.
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Affiliation(s)
- Rosalinda C Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294, United States.
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Ni P, Chung S. Mitochondrial Dysfunction in Schizophrenia. Bioessays 2020; 42:e1900202. [PMID: 32338416 DOI: 10.1002/bies.201900202] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/29/2020] [Indexed: 02/05/2023]
Abstract
Schizophrenia (SCZ) is a severe neurodevelopmental disorder affecting 1% of populations worldwide with a grave disability and socioeconomic burden. Current antipsychotic medications are effective treatments for positive symptoms, but poorly address negative symptoms and cognitive symptoms, warranting the development of better treatment options. Further understanding of SCZ pathogenesis is critical in these endeavors. Accumulating evidence has pointed to the role of mitochondria and metabolic dysregulation in SCZ pathogenesis. This review critically summarizes recent studies associating a compromised mitochondrial function with people with SCZ, including postmortem studies, imaging studies, genetic studies, and induced pluripotent stem cell studies. This review also discusses animal models with mitochondrial dysfunction resulting in SCZ-relevant neurobehavioral abnormalities, as well as restoration of mitochondrial function as potential therapeutic targets. Further understanding of mitochondrial dysfunction in SCZ may open the door to develop novel therapeutic strategies that can address the symptoms that cannot be adequately addressed by current antipsychotics alone.
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Affiliation(s)
- Peiyan Ni
- Psychiatric Laboratory and Mental Health Center, The State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Sangmi Chung
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
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7
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Bobilev AM, Perez JM, Tamminga CA. Molecular alterations in the medial temporal lobe in schizophrenia. Schizophr Res 2020; 217:71-85. [PMID: 31227207 DOI: 10.1016/j.schres.2019.06.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/29/2019] [Accepted: 06/01/2019] [Indexed: 11/30/2022]
Abstract
The medial temporal lobe (MTL) and its individual structures have been extensively implicated in schizophrenia pathophysiology, with considerable efforts aimed at identifying structural and functional differences in this brain region. The major structures of the MTL for which prominent differences have been revealed include the hippocampus, the amygdala and the superior temporal gyrus (STG). The different functions of each of these regions have been comprehensively characterized, and likely contribute differently to schizophrenia. While neuroimaging studies provide an essential framework for understanding the role of these MTL structures in various aspects of the disease, ongoing efforts have sought to employ molecular measurements in order to elucidate the biology underlying these macroscopic differences. This review provides a summary of the molecular findings in three major MTL structures, and discusses convergent findings in cellular architecture and inter-and intra-cellular networks. The findings of this effort have uncovered cell-type, network and gene-level specificity largely unique to each brain region, indicating distinct molecular origins of disease etiology. Future studies should test the functional implications of these molecular changes at the circuit level, and leverage new advances in sequencing technology to further refine our understanding of the differential contribution of MTL structures to schizophrenia.
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Affiliation(s)
- Anastasia M Bobilev
- Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, United States of America.
| | - Jessica M Perez
- Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, United States of America.
| | - Carol A Tamminga
- Department of Psychiatry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, United States of America.
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8
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Chan S, McCarthy M, Vawter MP. Psychiatric drugs impact mitochondrial function in brain and other tissues. Schizophr Res 2020; 217:136-147. [PMID: 31744750 PMCID: PMC7228833 DOI: 10.1016/j.schres.2019.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 09/14/2019] [Accepted: 09/16/2019] [Indexed: 12/31/2022]
Abstract
Mitochondria have been linked to the etiology of schizophrenia (SZ). However, studies of mitochondria in SZ might be confounded by the effects of pharmacological treatment with antipsychotic drugs (APDs) and other common medications. This review summarizes findings on relevant mitochondria mechanisms underlying SZ, and the potential impact of psychoactive drugs including primarily APDs, but also antidepressants and anxiolytics. The summarized data suggest that APDs impair mitochondria function by decreasing Complex I activity and ATP production and dissipation of the mitochondria membrane potential. At the same time, in the brains of patients with SZ, antipsychotic drug treatment normalizes gene expression modules enriched in mitochondrial genes that are decreased in SZ. This indicates that APDs may have both positive and negative effects on mitochondria. The available evidence suggests three conclusions i) alterations in mitochondria functions in SZ exist prior to APD treatment, ii) mitochondria alterations in SZ can be reversed by APD treatment, and iii) APDs directly cause impairment of mitochondria function. Overall, the mechanisms of action of psychiatric drugs on mitochondria are both direct and indirect; we conclude the effects of APDs on mitochondria may contribute to both their therapeutic and metabolic side effects. These studies support the hypothesis that neuronal mitochondria are an etiological factor in SZ. Moreover, APDs and other drugs must be considered in the evaluation of this pathophysiological role of mitochondria in SZ. Considering these effects, pharmacological actions on mitochondria may be a worthwhile target for further APD development.
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Affiliation(s)
- Shawna Chan
- Functional Genomics Laboratory, Department of Human Behavior and Psychiatry, University of California, Irvine, United States of America,School of Medicine University of California, Irvine, United States of America
| | - Michael McCarthy
- Psychiatry Service VA San Diego Healthcare System, Department of Psychiatry, University of California, San Diego, United States of America
| | - Marquis P. Vawter
- Functional Genomics Laboratory, Department of Human Behavior and Psychiatry, University of California, Irvine, United States of America,Corresponding author: Marquis P. Vawter, , Gillespie Neuroscience Research Facility, 829 Health Sciences Road, Irvine, CA 92697, Phone: 949-824-9014, Fax: 949-824-7012
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Bodenstein DF, Kim HK, Brown NC, Navaid B, Young LT, Andreazza AC. Mitochondrial DNA content and oxidation in bipolar disorder and its role across brain regions. NPJ SCHIZOPHRENIA 2019; 5:21. [PMID: 31797868 PMCID: PMC6892804 DOI: 10.1038/s41537-019-0089-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/18/2019] [Indexed: 12/18/2022]
Abstract
The underlying pathology of bipolar disorder remains unknown, though evidence is accumulating to support a role of mitochondrial dysfunction. In this study, we aim to investigate electron transport chain complex I subunit NDUFS7 protein expression; mtDNA content; common deletion; and oxidation in the Broadmann area 24 (BA24), cerebellum, hippocampus, and prefrontal cortex from patients with bipolar disorder, schizophrenia, and non-psychiatric controls. Here, we demonstrate no changes in NDUFS7 in BA24, cerebellum or hippocampus, increases in mtDNA content in hippocampus of patients with bipolar disorder, and decreases in mtDNA oxidation in patients with bipolar disorder and schizophrenia, respectively. Paired analysis between BA24 and cerebellum reveal increases within NDUFS7 levels and mtDNA content in cerebellum of patients with bipolar disorder or schizophrenia. We found a positive correlation between NDUFS7 and mtDNA content (ND4 and ND5) when combining brain regions. Our study supports the involvement of mitochondrial dysfunction in bipolar disorder and schizophrenia.
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Affiliation(s)
- D F Bodenstein
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - H K Kim
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - N C Brown
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - B Navaid
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - L T Young
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - A C Andreazza
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada. .,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
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E Silva LFS, Brito MD, Yuzawa JMC, Rosenstock TR. Mitochondrial Dysfunction and Changes in High-Energy Compounds in Different Cellular Models Associated to Hypoxia: Implication to Schizophrenia. Sci Rep 2019; 9:18049. [PMID: 31792231 PMCID: PMC6889309 DOI: 10.1038/s41598-019-53605-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 10/24/2019] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia (SZ) is a multifactorial mental disorder, which has been associated with a number of environmental factors, such as hypoxia. Considering that numerous neural mechanisms depends on energetic supply (ATP synthesis), the maintenance of mitochondrial metabolism is essential to keep cellular balance and survival. Therefore, in the present work, we evaluated functional parameters related to mitochondrial function, namely calcium levels, mitochondrial membrane potential, redox homeostasis, high-energy compounds levels and oxygen consumption, in astrocytes from control (Wistar) and Spontaneously Hypertensive Rats (SHR) animals exposed both to chemical and gaseous hypoxia. We show that astrocytes after hypoxia presented depolarized mitochondria, disturbances in Ca2+ handling, destabilization in redox system and alterations in ATP, ADP, Pyruvate and Lactate levels, in addition to modification in NAD+/NADH ratio, and Nfe2l2 and Nrf1 expression. Interestingly, intrauterine hypoxia also induced augmentation in mitochondrial biogenesis and content. Altogether, our data suggest that hypoxia can induce mitochondrial deregulation and a decrease in energy metabolism in the most prevalent cell type in the brain, astrocytes. Since SHR are also considered an animal model of SZ, our results can likewise be related to their phenotypic alterations and, therefore, our work also allow an increase in the knowledge of this burdensome disorder.
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Czarny P, Bialek K, Ziolkowska S, Strycharz J, Sliwinski T. DNA damage and repair in neuropsychiatric disorders. What do we know and what are the future perspectives? Mutagenesis 2019; 35:79-106. [DOI: 10.1093/mutage/gez035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/27/2019] [Indexed: 12/11/2022] Open
Abstract
AbstractOver the past two decades, extensive research has been done to elucidate the molecular etiology and pathophysiology of neuropsychiatric disorders. In majority of them, including Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), bipolar disorder (BD), schizophrenia and major depressive disorder, increased oxidative and nitrosative stress was found. This stress is known to induce oxidative damage to biomolecules, including DNA. Accordingly, increased mitochondrial and nuclear DNA, as well as RNA damage, were observed in patients suffering from these diseases. However, recent findings indicate that the patients are characterised by impaired DNA repair pathways, which may suggest that these DNA lesions could be also a result of their insufficient repair. In the current systematic, critical review, we aim to sum up, using available literature, the knowledge about the involvement of nuclear and mitochondrial DNA damage and repair, as well as about damage to RNA in pathoetiology of neuropsychiatric disorders, i.e., AD, PD, ALS, BD, schizophrenia and major depressive disorder, as well as the usefulness of the discussed factors as being diagnostic markers and targets for new therapies. Moreover, we also underline the new directions to which future studies should head to elucidate these phenomena.
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Affiliation(s)
- Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Katarzyna Bialek
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Sylwia Ziolkowska
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Justyna Strycharz
- Department of Medical Biochemistry, Medical University of Lodz, Lodz, Poland
| | - Tomasz Sliwinski
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
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Kasahara T, Kato T. What Can Mitochondrial DNA Analysis Tell Us About Mood Disorders? Biol Psychiatry 2018; 83:731-738. [PMID: 29102411 DOI: 10.1016/j.biopsych.2017.09.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/11/2017] [Accepted: 09/12/2017] [Indexed: 12/11/2022]
Abstract
Variants in mitochondrial DNA (mtDNA) and nuclear genes encoding mitochondrial proteins in bipolar disorder, depression, or other psychiatric disorders have been studied for decades, since mitochondrial dysfunction was first suggested in the brains of patients with these diseases. Candidate gene association studies initially resulted in findings compatible with the mitochondrial dysfunction hypothesis. Many of those studies, however, were conducted with modest sample sizes (N < 1000), which could cause false positive findings. Furthermore, the DNA samples examined in these studies, including genome-wide association studies, were generally derived from peripheral tissues. One key unanswered question is whether there is an association between mood disorders and somatic mtDNA mutations (deletions and point mutations) in brain regions that accumulate a high amount of mtDNA mutations and/or are involved in the regulation of mood. Two lines of robust evidence supporting the importance of mtDNA mutations in brain tissues for mood disorders have come from clinical observation of mitochondrial disease patients who carry primary mtDNA mutations or accumulate secondary mtDNA mutations due to nuclear mutations and an animal model study. More than half of mitochondrial disease patients have comorbid mood disorders, and mice with neuron-specific accumulation of mtDNA mutations show spontaneous depression-like episodes. In this review, we first summarize the current knowledge of mtDNA and its genetics and discuss what mtDNA analysis tells us about neuropsychiatric disorders based on an example of Parkinson's disease. We also discuss challenges and future directions beyond mtDNA analysis toward an understanding of the pathophysiology of "idiopathic" mood disorders.
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Affiliation(s)
- Takaoki Kasahara
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Wako-shi, Saitama, Japan
| | - Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Wako-shi, Saitama, Japan.
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Rollins BL, Morgan L, Hjelm BE, Sequeira A, Schatzberg AF, Barchas JD, Lee FS, Myers RM, Watson SJ, Akil H, Potkin SG, Bunney WE, Vawter MP. Mitochondrial Complex I Deficiency in Schizophrenia and Bipolar Disorder and Medication Influence. MOLECULAR NEUROPSYCHIATRY 2017; 3:157-169. [PMID: 29594135 DOI: 10.1159/000484348] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/16/2017] [Indexed: 12/22/2022]
Abstract
Subjects with schizophrenia (SZ) and bipolar disorder (BD) show decreased protein and transcript levels for mitochondrial complex I. In vitro results suggest antipsychotic and antidepressant drugs may be responsible. We measured complex I activity in BD, SZ, and controls and presence of antipsychotic and antidepressant medications, mitochondrial DNA (mtDNA) copy number, and the mtDNA "common deletion" in the brain. Complex I activity in the prefrontal cortex was decreased by 45% in SZ compared to controls (p = 0.02), while no significant difference was found in BD. Complex I activity was significantly decreased (p = 0.01) in pooled cases (SZ and BD) that had detectable psychotropic medications and drugs compared to pooled cases with no detectable levels. Subjects with age at onset in their teens and psychotropic medications showed decreased (p < 0.05) complex I activity compared to subjects with an adult age at onset. Both SZ and BD groups displayed significant increases (p < 0.05) in mtDNA copy number compared to controls; however, common deletion burden was not altered. Complex I deficiency is found in SZ brain tissue, and psychotropic medications may play a role in mitochondrial dysfunction. Studies of medication-free first-episode psychosis patients are needed to elucidate whether mitochondrial pathophysiology occurs independent of medication effects.
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Affiliation(s)
- Brandi L Rollins
- Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
| | - Ling Morgan
- Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
| | - Brooke E Hjelm
- Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
| | - Adolfo Sequeira
- Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
| | - Alan F Schatzberg
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
| | - Jack D Barchas
- Department of Psychiatry, Weill Cornell Medical College, Ithaca, NJ, USA
| | - Francis S Lee
- Department of Psychiatry, Weill Cornell Medical College, Ithaca, NJ, USA
| | - Rick M Myers
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | | | - Huda Akil
- MBNI, University of Michigan, Ann Arbor, MI, USA
| | - Steven G Potkin
- Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
| | - William E Bunney
- Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
| | - Marquis P Vawter
- Functional Genomics Laboratory, Department of Psychiatry & Human Behavior, University of California, Irvine, CA, USA
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Roberts RC. Postmortem studies on mitochondria in schizophrenia. Schizophr Res 2017; 187:17-25. [PMID: 28189530 PMCID: PMC5550365 DOI: 10.1016/j.schres.2017.01.056] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/27/2017] [Accepted: 01/30/2017] [Indexed: 01/02/2023]
Abstract
The aim of this paper is to provide a brief review of mitochondrial structure as it relates to function and then present abnormalities in mitochondria in postmortem schizophrenia with a focus on ultrastructure. Function, morphology, fusion, fission, motility, ΔΨmem, ATP production, mitochondrial derived vesicles, and mitochondria-associated ER membranes will be briefly covered. Pathology in mitochondria has long been implicated in schizophrenia, as shown by genetic, proteomic, enzymatic and anatomical abnormalities. The cortex and basal ganglia will be reviewed. In the anterior cingulate cortex, the number of mitochondria per neuronal somata in layers 5/6 in schizophrenia is decreased by 43%. There are also fewer mitochondria in terminals forming axospinous synapses. In the caudate and putamen the number of mitochondria is abnormal in both glial cells and neurons in schizophrenia subjects, the extent of which depends on treatment, response and predominant lifetime symptoms. Treatment-responsive schizophrenia subjects had about a 40% decrease in the number of mitochondria per synapse in the caudate nucleus and putamen, while treatment resistant cases had normal values. A decrease in mitochondrial density in the neuropil distinguishes paranoid from undifferentiated schizophrenia. The appearance, size and density of mitochondria were normal in the nucleus accumbens. In the substantia nigra, COX subunits were affected in rostral regions. Mitochondrial hyperplasia occurs within axon terminals that synapse onto dopamine neurons, but mitochondria in dopamine neuronal somata are similar in size and number. In schizophrenia, mitochondria are differentially affected depending on the brain region, cell type, subcellular location, treatment status, treatment response and symptoms.
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Affiliation(s)
- Rosalinda C. Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama, Birmingham, AL 35294
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15
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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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Föcking M, Dicker P, Lopez LM, Hryniewiecka M, Wynne K, English JA, Cagney G, Cotter DR. Proteomic analysis of the postsynaptic density implicates synaptic function and energy pathways in bipolar disorder. Transl Psychiatry 2016; 6:e959. [PMID: 27898073 PMCID: PMC5290351 DOI: 10.1038/tp.2016.224] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 09/26/2016] [Accepted: 09/28/2016] [Indexed: 12/17/2022] Open
Abstract
The postsynaptic density (PSD) contains a complex set of proteins of known relevance to neuropsychiatric disorders such as schizophrenia and bipolar disorder. We enriched for this anatomical structure in the anterior cingulate cortex of 16 bipolar disorder samples and 20 controls from the Stanley Medical Research Institute. Unbiased shotgun proteomics incorporating label-free quantitation was used to identify differentially expressed proteins. Quantitative investigation of the PSD identified 2033 proteins, among which 288 were found to be differentially expressed. Validation of expression changes of DNM1, DTNA, NDUFV2, SEPT11 and SSBP was performed by western blotting. Bioinformatics analysis of the differentially expressed proteins implicated metabolic pathways including mitochondrial function, the tricarboxylic acid cycle, oxidative phosphorylation, protein translation and calcium signaling. The data implicate PSD-associated proteins, and specifically mitochondrial function in bipolar disorder. They relate synaptic function in bipolar disorder and the energy pathways that underpin it. Overall, our findings add to a growing literature linking the PSD and mitochondrial function in psychiatric disorders generally, and suggest that mitochondrial function associated with the PSD is particularly important in bipolar disorder.
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Affiliation(s)
- M Föcking
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland,Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Education and Research Centre, Dublin 9, Ireland. E-mail: or
| | - P Dicker
- Departments of Epidemiology and Public Health, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - L M Lopez
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - M Hryniewiecka
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - K Wynne
- Proteome Research Centre, UCD Conway Institute of Biomolecular and Biomedical Research, School of Medicine and Medical Sciences, University College Dublin, Dublin, Ireland
| | - J A English
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - G Cagney
- Proteome Research Centre, UCD Conway Institute of Biomolecular and Biomedical Research, School of Medicine and Medical Sciences, University College Dublin, Dublin, Ireland
| | - D R Cotter
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland,Department of Psychiatry, Beaumont Hospital, Dublin, Ireland,Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Education and Research Centre, Dublin 9, Ireland. E-mail: or
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17
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Lal A, Gomez E, Calloway C. Increased mitochondrial DNA deletions and copy number in transfusion-dependent thalassemia. JCI Insight 2016; 1. [PMID: 27583305 DOI: 10.1172/jci.insight.88150] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Iron overload is the primary cause of morbidity in transfusion-dependent thalassemia. Increase in iron causes mitochondrial dysfunction under experimental conditions, but the occurrence and significance of mitochondrial damage is not understood in patients with thalassemia. METHODS Mitochondrial DNA (mtDNA) to nuclear DNA copy number (Mt/N) and frequency of the common 4977-bp mitochondrial deletion (ΔmtDNA4977) were quantified using a quantitative PCR assay on whole blood samples from 38 subjects with thalassemia who were receiving regular transfusions. RESULTS Compared with healthy controls, Mt/N and ΔmtDNA4977 frequency were elevated in thalassemia (P = 0.038 and P < 0.001, respectively). ΔmtDNA4977 was increased in the presence of either liver iron concentration > 15 mg/g dry-weight or splenectomy, with the highest levels observed in subjects who had both risk factors (P = 0.003). Myocardial iron (MRI T2* < 20 ms) was present in 0%, 22%, and 46% of subjects with ΔmtDNA4977 frequency < 20, 20-40, and > 40/1 × 107 mtDNA, respectively (P = 0.025). Subjects with Mt/N values below the group median had significantly lower Matsuda insulin sensitivity index (5.76 ± 0.53) compared with the high Mt/N group (9.11 ± 0.95, P = 0.008). CONCLUSION Individuals with transfusion-dependent thalassemia demonstrate age-related increase in mtDNA damage in leukocytes. These changes are markedly amplified by splenectomy and are associated with extrahepatic iron deposition. Elevated mtDNA damage in blood cells may predict the risk of iron-associated organ damage in thalassemia.
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Affiliation(s)
- Ashutosh Lal
- Hematology/Oncology, UCSF Benioff Children's Hospital, Oakland, California, USA; Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Esteban Gomez
- Hematology/Oncology, UCSF Benioff Children's Hospital, Oakland, California, USA
| | - Cassandra Calloway
- Children's Hospital Oakland Research Institute, Oakland, California, USA; Forensic Science Graduate Group, University of California, Davis, California, USA
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DNA Damage and Repair in Schizophrenia and Autism: Implications for Cancer Comorbidity and Beyond. Int J Mol Sci 2016; 17:ijms17060856. [PMID: 27258260 PMCID: PMC4926390 DOI: 10.3390/ijms17060856] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/12/2016] [Accepted: 05/27/2016] [Indexed: 12/16/2022] Open
Abstract
Schizophrenia and autism spectrum disorder (ASD) are multi-factorial and multi-symptomatic psychiatric disorders, each affecting 0.5%-1% of the population worldwide. Both are characterized by impairments in cognitive functions, emotions and behaviour, and they undermine basic human processes of perception and judgment. Despite decades of extensive research, the aetiologies of schizophrenia and ASD are still poorly understood and remain a significant challenge to clinicians and scientists alike. Adding to this unsatisfactory situation, patients with schizophrenia or ASD often develop a variety of peripheral and systemic disturbances, one prominent example of which is cancer, which shows a direct (but sometimes inverse) comorbidity in people affected with schizophrenia and ASD. Cancer is a disease characterized by uncontrolled proliferation of cells, the molecular origin of which derives from mutations of a cell's DNA sequence. To counteract such mutations and repair damaged DNA, cells are equipped with intricate DNA repair pathways. Oxidative stress, oxidative DNA damage, and deficient repair of oxidative DNA lesions repair have been proposed to contribute to the development of schizophrenia and ASD. In this article, we summarize the current evidence of cancer comorbidity in these brain disorders and discuss the putative roles of oxidative stress, DNA damage and DNA repair in the aetiopathology of schizophrenia and ASD.
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Abstract
OBJECTIVE In this work, we evaluated the association of human immunodeficiency virus (HIV) infection and methamphetamine (METH) use with mitochondrial injury in the brain and its implication on neurocognitive impairment. DESIGN Mitochondria carry their genome (mtDNA) and play a critical role in cellular processes in the central nervous system. METH is commonly used in HIV-infected populations. HIV infection and METH use can cause damage to mtDNA and lead to neurocognitive morbidity. We evaluated HIV infection and METH use with mitochondrial injury in the brain. METHODS We obtained white and gray matter from Brodmann areas 7, 8, 9, 46 of the following: HIV-infected individuals with history of past METH use (HIV+METH+, n = 16), HIV-infected individuals with no history of past METH use (HIV+METH-, n = 11), and HIV-negative controls (HIV-METH-, n = 30). We used the 'common deletion', a 4977 bp mutation, as a measurement of mitochondrial injury, and quantified levels of mtDNA and 'common deletion' by droplet digital PCR, and evaluated in relation to neurocognitive functioning [Global Deficit Score (GDS)]. RESULTS Levels of mtDNA and mitochondrial injury were highest in white matter of Brodmann area 46. A higher relative proportion of mtDNA carrying the 'common deletion' was associated with lower GDS (P < 0.01) in HIV+METH+ but higher GDS (P < 0.01) in HIV+METH-. CONCLUSIONS Increased mitochondrial injury was associated with worse neurocognitive function in HIV+METH- individuals. Among HIV+METH+ individuals, an opposite effect was seen.
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Mitochondrial genome variations and functional characterization in Han Chinese families with schizophrenia. Schizophr Res 2016; 171:200-6. [PMID: 26822593 DOI: 10.1016/j.schres.2016.01.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 12/09/2015] [Accepted: 01/04/2016] [Indexed: 11/23/2022]
Abstract
The relationship between mitochondrial DNA (mtDNA) variants and schizophrenia has been strongly debated. To test whether mtDNA variants are involved in schizophrenia in Han Chinese patients, we sequenced the entire mitochondrial genomes of probands from 11 families with a family history and maternal inheritance pattern of schizophrenia. Besides the haplogroup-specific variants, we found 11 nonsynonymous private variants, one rRNA variant, and one tRNA variant in 5 of 11 probands. Among the nonsynonymous private variants, mutations m.15395 A>G and m.8536 A>G were predicted to be deleterious after web-based searches and in silico program affiliated analysis. Functional characterization further supported the potential pathogenicity of the two variants m.15395 A>G and m.8536 A>G to cause mitochondrial dysfunction at the cellular level. Our results showed that mtDNA variants were actively involved in schizophrenia in some families with maternal inheritance of this disease.
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Abstract
Accumulating evidence suggests an important contribution of reactive oxygen species (ROS) to pain and neuropsychiatric disorders, but their role in pain-related plasticity in the brain is largely unknown. Neuroplasticity in the central nucleus of the amygdala (CeA) correlates positively with pain behaviors in different models. Little is known, however, about mechanisms of visceral pain-related amygdala changes. The electrophysiological and behavioral studies reported here addressed the role of ROS in the CeA in a visceral pain model induced by intracolonic zymosan. Vocalizations to colorectal distension and anxiety-like behavior increased after intracolonic zymosan and were inhibited by intra-CeA application of a ROS scavenger (tempol, a superoxide dismutase mimetic). Tempol also induced a place preference in zymosan-treated rats but not in controls. Single-unit recordings of CeA neurons in anesthetized rats showed increases of background activity and responses to visceral stimuli after intracolonic zymosan. Intra-CeA application of tempol inhibited the increased activity but had no effect under normal conditions. Whole-cell patch-clamp recordings of CeA neurons in brain slices from zymosan-treated rats showed that tempol decreased neuronal excitability and excitatory synaptic transmission of presumed nociceptive inputs from the brainstem (parabrachial area) through a combination of presynaptic and postsynaptic actions. Tempol had no effect in brain slices from sham controls. The results suggest that ROS contribute to visceral pain-related hyperactivity of amygdala neurons and amygdala-dependent behaviors through a mechanism that involves increased excitatory transmission and excitability of CeA neurons.
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Nod-like receptor pyrin containing 3 (NLRP3) in the post-mortem frontal cortex from patients with bipolar disorder: A potential mediator between mitochondria and immune-activation. J Psychiatr Res 2016; 72:43-50. [PMID: 26540403 DOI: 10.1016/j.jpsychires.2015.10.015] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 10/08/2015] [Accepted: 10/22/2015] [Indexed: 12/22/2022]
Abstract
Mitochondrial complex I dysfunction, oxidative stress and immune-activation are consistently reported in bipolar disorder (BD). Mitochondrial production of reactive oxygen species was recently linked to activation of an inflammatory redox sensor, the nod-like receptor family pyrin domain-containing 3 (NLRP3). Upon its activation, NLRP3 recruits apoptosis-associated speck-like protein (ASC) and caspase-1 to form the NLRP3-inflammasome, activating IL-1β. This study aimed to examine if immune-activation may be a downstream target of complex I dysfunction through the NLRP3-inflammasome in BD. Post-mortem frontal cortex from patients with BD (N = 9), schizophrenia (N = 10), and non-psychiatric controls (N = 9) were donated from the Harvard Brain Tissue Resource Center. Levels of NLRP3, ASC and caspase-1 were measured by western blotting, ELISA and Luminex. While we found no effects of age, sex or post-mortem delay, lower levels of complex I (F2,25 = 3.46, p < 0.05) and NDUFS7, a subunit of complex I (F2,25 = 4.13, p < 0.05), were found in patients with BD. Mitochondrial NLRP3 (F2,25 = 3.86, p < 0.05) and ASC (F2,25 = 4.61, p < 0.05) levels were higher in patients with BD. However, levels of caspase 1 (F2,25 = 4.13, p < 0.05 for both), IL-1β (F2,25 = 7.05, p < 0.01), IL-6 (F2,25 = 5.48, p < 0.05), TNFα (F2,25 = 7.14, p < 0.01) and IL-10 (F2,25 = 5.02, p < 0.05) were increased in both BD and schizophrenia. These findings suggest that immune-activation in the frontal cortex may occur both in patients with BD and schizophrenia, while complex I dysfunction and NLRP3-inflammasome activation may be more specific to BD.
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23
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Hjelm BE, Rollins B, Mamdani F, Lauterborn JC, Kirov G, Lynch G, Gall CM, Sequeira A, Vawter MP. Evidence of Mitochondrial Dysfunction within the Complex Genetic Etiology of Schizophrenia. MOLECULAR NEUROPSYCHIATRY 2015; 1:201-19. [PMID: 26550561 DOI: 10.1159/000441252] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 09/22/2015] [Indexed: 01/19/2023]
Abstract
Genetic evidence has supported the hypothesis that schizophrenia (SZ) is a polygenic disorder caused by the disruption in function of several or many genes. The most common and reproducible cellular phenotype associated with SZ is a reduction in dendritic spines within the neocortex, suggesting alterations in dendritic architecture may cause aberrant cortical circuitry and SZ symptoms. Here, we review evidence supporting a multifactorial model of mitochondrial dysfunction in SZ etiology and discuss how these multiple paths to mitochondrial dysfunction may contribute to dendritic spine loss and/or underdevelopment in some SZ subjects. The pathophysiological role of mitochondrial dysfunction in SZ is based upon genomic analyses of both the mitochondrial genome and nuclear genes involved in mitochondrial function. Previous studies and preliminary data suggest SZ is associated with specific alleles and haplogroups of the mitochondrial genome, and also correlates with a reduction in mitochondrial copy number and an increase in synonymous and nonsynonymous substitutions of mitochondrial DNA. Mitochondrial dysfunction has also been widely implicated in SZ by genome-wide association, exome sequencing, altered gene expression, proteomics, microscopy analyses, and induced pluripotent stem cell studies. Together, these data support the hypothesis that SZ is a polygenic disorder with an enrichment of mitochondrial targets.
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Affiliation(s)
- Brooke E Hjelm
- Departments of Psychiatry & Human Behavior, University of California, Irvine, Calif., USA
| | - Brandi Rollins
- Departments of Psychiatry & Human Behavior, University of California, Irvine, Calif., USA
| | - Firoza Mamdani
- Departments of Psychiatry & Human Behavior, University of California, Irvine, Calif., USA
| | - Julie C Lauterborn
- Departments of Anatomy & Neurobiology, University of California, Irvine, Calif., USA
| | - George Kirov
- MRC Centre for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Gary Lynch
- Departments of Psychiatry & Human Behavior, University of California, Irvine, Calif., USA; Departments of Anatomy & Neurobiology, University of California, Irvine, Calif., USA
| | - Christine M Gall
- Departments of Anatomy & Neurobiology, University of California, Irvine, Calif., USA; Departments of Neurobiology & Behavior, University of California, Irvine, Calif., USA
| | - Adolfo Sequeira
- Departments of Psychiatry & Human Behavior, University of California, Irvine, Calif., USA
| | - Marquis P Vawter
- Departments of Psychiatry & Human Behavior, University of California, Irvine, Calif., USA
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McCollum LA, Walker CK, Roche JK, Roberts RC. Elevated Excitatory Input to the Nucleus Accumbens in Schizophrenia: A Postmortem Ultrastructural Study. Schizophr Bull 2015; 41:1123-32. [PMID: 25817135 PMCID: PMC4535638 DOI: 10.1093/schbul/sbv030] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The cause of schizophrenia (SZ) is unknown and no single region of the brain can be pinpointed as an area of primary pathology. Rather, SZ results from dysfunction of multiple neurotransmitter systems and miswiring between brain regions. It is necessary to elucidate how communication between regions is disrupted to advance our understanding of SZ pathology. The nucleus accumbens (NAcc) is a prime region of interest, where inputs from numerous brain areas altered in SZ are integrated. Aberrant signaling in the NAcc is hypothesized to cause symptoms of SZ, but it is unknown if these abnormalities are actually present. Electron microscopy was used to study the morphology of synaptic connections in SZ. The NAcc core and shell of 6 SZ subjects and 8 matched controls were compared in this pilot study. SZ subjects had a 19% increase in the density of asymmetric axospinous synapses (characteristic of excitatory inputs) in the core, but not the shell. Both groups had similar densities of symmetric synapses (characteristic of inhibitory inputs). The postsynaptic densities of asymmetric synapses had 22% smaller areas in the core, but not the shell. These results indicate that the core receives increased excitatory input in SZ, potentially leading to dysfunctional dopamine neurotransmission and cortico-striatal-thalamic stimulus processing. The reduced postsynaptic density size of asymmetric synapses suggests impaired signaling at these synapses. These findings enhance our understanding of the role the NAcc might play in SZ and the interaction of glutamatergic and dopaminergic abnormalities in SZ.
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Affiliation(s)
- Lesley A. McCollum
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL;,*To whom correspondence should be addressed; Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Sparks Center 841, 1720 2nd Avenue South, Birmingham, AL 35294, US; tel: +1-205-934-1858, fax: +1-205-996-9377, e-mail:
| | - Courtney K. Walker
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL
| | - Joy K. Roche
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL
| | - Rosalinda C. Roberts
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL
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Tendler RMD, Loike JD. Mitochondrial Replacement Therapy: Halachic Considerations for Enrolling in an Experimental Clinical Trial. Rambam Maimonides Med J 2015; 6:RMMJ.10216. [PMID: 26241230 PMCID: PMC4524404 DOI: 10.5041/rmmj.10216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transition of new biotechnologies into clinical trials is a critical step in approving a new drug or therapy in health care. Ethically recruiting appropriate volunteers for these clinical trials can be a challenging task for both the pharmaceutical companies and the US Food and Drug Administration. In this paper we analyze the Jewish halachic perspectives of volunteering for clinical trials by focusing on an innovative technology in reproductive medicine, mitochondrial replacement therapy. The halachic perspective encourages individuals to volunteer for such clinical trials under the ethical principles of beneficence and social responsibility, when animal studies have shown that health risks are minimal.
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Affiliation(s)
- Rabbi Moshe D. Tendler
- Rosh Yeshiva, Rabbi Isaac Elchanan Rabbinical Theological Seminary, the Rabbi Isaac and Bella Tendler Professor of Jewish Medical Ethics and Professor of Biology, Department of Biology, Yeshiva University, New York, USA
| | - John D. Loike
- Director of Special Programs, Center for Bioethics, Columbia University, New York, USA
- To whom correspondence should be addressed. E-mail:
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