51
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Mitochondrial DNA Methylation and Human Diseases. Int J Mol Sci 2021; 22:ijms22094594. [PMID: 33925624 PMCID: PMC8123858 DOI: 10.3390/ijms22094594] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/23/2021] [Accepted: 04/25/2021] [Indexed: 12/12/2022] Open
Abstract
Epigenetic modifications of the nuclear genome, including DNA methylation, histone modifications and non-coding RNA post-transcriptional regulation, are increasingly being involved in the pathogenesis of several human diseases. Recent evidence suggests that also epigenetic modifications of the mitochondrial genome could contribute to the etiology of human diseases. In particular, altered methylation and hydroxymethylation levels of mitochondrial DNA (mtDNA) have been found in animal models and in human tissues from patients affected by cancer, obesity, diabetes and cardiovascular and neurodegenerative diseases. Moreover, environmental factors, as well as nuclear DNA genetic variants, have been found to impair mtDNA methylation patterns. Some authors failed to find DNA methylation marks in the mitochondrial genome, suggesting that it is unlikely that this epigenetic modification plays any role in the control of the mitochondrial function. On the other hand, several other studies successfully identified the presence of mtDNA methylation, particularly in the mitochondrial displacement loop (D-loop) region, relating it to changes in both mtDNA gene transcription and mitochondrial replication. Overall, investigations performed until now suggest that methylation and hydroxymethylation marks are present in the mtDNA genome, albeit at lower levels compared to those detectable in nuclear DNA, potentially contributing to the mitochondria impairment underlying several human diseases.
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52
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Breton S, Ghiselli F, Milani L. Mitochondrial Short-Term Plastic Responses and Long-Term Evolutionary Dynamics in Animal Species. Genome Biol Evol 2021; 13:6248094. [PMID: 33892508 PMCID: PMC8290114 DOI: 10.1093/gbe/evab084] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 04/13/2021] [Accepted: 04/20/2021] [Indexed: 12/15/2022] Open
Abstract
How do species respond or adapt to environmental changes? The answer to this depends partly on mitochondrial epigenetics and genetics, new players in promoting adaptation to both short- and long-term environmental changes. In this review, we explore how mitochondrial epigenetics and genetics mechanisms, such as mtDNA methylation, mtDNA-derived noncoding RNAs, micropeptides, mtDNA mutations, and adaptations, can contribute to animal plasticity and adaptation. We also briefly discuss the challenges in assessing mtDNA adaptive evolution. In sum, this review covers new advances in the field of mitochondrial genomics, many of which are still controversial, and discusses processes still somewhat obscure, and some of which are still quite speculative and require further robust experimentation.
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Affiliation(s)
- Sophie Breton
- Department of Biological Sciences, University of Montreal, Quebec, Canada
| | - Fabrizio Ghiselli
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
| | - Liliana Milani
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
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53
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Goldsmith C, Rodríguez-Aguilera JR, El-Rifai I, Jarretier-Yuste A, Hervieu V, Raineteau O, Saintigny P, Chagoya de Sánchez V, Dante R, Ichim G, Hernandez-Vargas H. Low biological fluctuation of mitochondrial CpG and non-CpG methylation at the single-molecule level. Sci Rep 2021; 11:8032. [PMID: 33850190 PMCID: PMC8044111 DOI: 10.1038/s41598-021-87457-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 03/30/2021] [Indexed: 12/16/2022] Open
Abstract
Mammalian cytosine DNA methylation (5mC) is associated with the integrity of the genome and the transcriptional status of nuclear DNA. Due to technical limitations, it has been less clear if mitochondrial DNA (mtDNA) is methylated and whether 5mC has a regulatory role in this context. Here, we used bisulfite-independent single-molecule sequencing of native human and mouse DNA to study mitochondrial 5mC across different biological conditions. We first validated the ability of long-read nanopore sequencing to detect 5mC in CpG (5mCpG) and non-CpG (5mCpH) context in nuclear DNA at expected genomic locations (i.e. promoters, gene bodies, enhancers, and cell type-specific transcription factor binding sites). Next, using high coverage nanopore sequencing we found low levels of mtDNA CpG and CpH methylation (with several exceptions) and little variation across biological processes: differentiation, oxidative stress, and cancer. 5mCpG and 5mCpH were overall higher in tissues compared to cell lines, with small additional variation between cell lines of different origin. Despite general low levels, global and single-base differences were found in cancer tissues compared to their adjacent counterparts, in particular for 5mCpG. In conclusion, nanopore sequencing is a useful tool for the detection of modified DNA bases on mitochondria that avoid the biases introduced by bisulfite and PCR amplification. Enhanced nanopore basecalling models will provide further resolution on the small size effects detected here, as well as rule out the presence of other DNA modifications such as oxidized forms of 5mC.
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Affiliation(s)
- Chloe Goldsmith
- Department of Tumor Escape, Resistance and Immunity, TGF-Beta and Immuno-Regulation Team, Cancer Research Centre of Lyon (CRCL), INSERM U 1052, CNRS UMR 5286, UCBL1, Université de Lyon, Centre Léon Bérard, 28 rue Laennec, 69373, Lyon Cedex 08, France.
| | - Jesús Rafael Rodríguez-Aguilera
- Department of Cellular Biology and Development, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Mexico City, Mexico
| | - Ines El-Rifai
- Department of Tumor Escape, Resistance and Immunity, TGF-Beta and Immuno-Regulation Team, Cancer Research Centre of Lyon (CRCL), INSERM U 1052, CNRS UMR 5286, UCBL1, Université de Lyon, Centre Léon Bérard, 28 rue Laennec, 69373, Lyon Cedex 08, France
| | - Adrien Jarretier-Yuste
- Department of Tumor Escape, Resistance and Immunity, TGF-Beta and Immuno-Regulation Team, Cancer Research Centre of Lyon (CRCL), INSERM U 1052, CNRS UMR 5286, UCBL1, Université de Lyon, Centre Léon Bérard, 28 rue Laennec, 69373, Lyon Cedex 08, France
| | - Valérie Hervieu
- Department of Surgical Pathology, Hospices Civils de Lyon, Groupement Hospitalier Est, Lyon, France
| | - Olivier Raineteau
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM, Stem Cell and Brain Research Institute U1208, Bron, France
| | - Pierre Saintigny
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, Lyon, France
- Department of Translational Medicine, Centre Léon Bérard, Lyon, France
| | - Victoria Chagoya de Sánchez
- Department of Cellular Biology and Development, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, 04510, Mexico City, Mexico
| | - Robert Dante
- Dependence Receptors Cancer and Development Laboratory, Department of Signaling of Tumoral Escape. Cancer Research. Center of Lyon (CRCL), Inserm U 1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, 28 rue Laennec, 69373, Lyon Cedex 08, France
| | - Gabriel Ichim
- Cancer Cell Death Laboratory, Part of LabEx DEVweCAN, Université de Lyon, Lyon, France
- Cancer Research Centre of Lyon (CRCL), Inserm U 1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, 28 rue Laennec, 69373, Lyon Cedex 08, France
| | - Hector Hernandez-Vargas
- Department of Tumor Escape, Resistance and Immunity, TGF-Beta and Immuno-Regulation Team, Cancer Research Centre of Lyon (CRCL), INSERM U 1052, CNRS UMR 5286, UCBL1, Université de Lyon, Centre Léon Bérard, 28 rue Laennec, 69373, Lyon Cedex 08, France.
- Department of Translational Medicine, Centre Léon Bérard, Lyon, France.
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54
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Pérez-Muñoz AA, de Lourdes Muñoz M, García-Hernández N, Santander-Lucio H. A New Approach to Identify the Methylation Sites in the Control Region of Mitochondrial DNA. Curr Mol Med 2021; 21:151-164. [PMID: 32484108 DOI: 10.2174/1566524020666200528154005] [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: 12/28/2019] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 11/22/2022]
Abstract
Mitochondrial DNA (mtDNA) methylation has the potential to be used as a biomarker of human development or disease. However, mtDNA methylation procedures are costly and time-consuming. Therefore, we developed a new approach based on an RT-PCR assay for the base site identification of methylated cytosine in the control region of mtDNA through a simple, fast, specific, and low-cost strategy. Total DNA was purified, and methylation was determined by RT-PCR bisulfite sequencing. This procedure included the DNA purification, bisulfite treatment and RT-PCR amplification of the control region divided into three subregions with specific primers. Sequences obtained with and without the bisulfite treatment were compared to identify the methylated cytosine dinucleotides. Furthermore, the efficiency of C to U conversion of cytosines was assessed by including a negative control. Interestingly, mtDNA methylation was observed mainly within non-Cphosphate- G (non-CpG) dinucleotides and mostly in the regions containing regulatory elements, such as OH or CSBI, CSBII, and CSBIII. This new approach will promote the generation of new information regarding mtDNA methylation patterns in samples from patients with different pathologies or that are exposed to a toxic environment in diverse human populations.
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Affiliation(s)
- Ashael Alfredo Pérez-Muñoz
- Department of Genetics and Molecular Biology, Research and Advanced Studies Center of National Polytechnic Institute (CINVESTAV of IPN), Mexico City, Mexico
| | - María de Lourdes Muñoz
- Department of Genetics and Molecular Biology, Research and Advanced Studies Center of National Polytechnic Institute (CINVESTAV of IPN), Mexico City, Mexico
| | - Normand García-Hernández
- Unidad de Investigacion Medica en Genetica Humana, Unidad Medica de Alta Especialidad Hospital de Pediatria "Dr. Silvestre Frenk Freund", Centro Medico Nacional "Siglo XXI", Instituto Mexicano del Seguro Social (IMSS), Mexico City, Mexico
| | - Heriberto Santander-Lucio
- Department of Genetics and Molecular Biology, Research and Advanced Studies Center of National Polytechnic Institute (CINVESTAV of IPN), Mexico City, Mexico
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55
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Leroux É, Brosseau C, Angers B, Angers A, Breton S. [Mitochondrial DNA methylation: Controversies, issues and perspectives]. Med Sci (Paris) 2021; 37:258-264. [PMID: 33739273 DOI: 10.1051/medsci/2021011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
DNA methylation is an epigenetic mechanism that has been largely probed regarding eukaryotic nuclear genome and bacteria, and its role is especially crucial in the regulation of gene expression. In mammals, it is almost exclusively acting on a cytosine preceding a guanine (CpG), whereas it presents itself mainly in a non-CpG context in bacteria's DNA. Conversely to nuclear and bacterial genomes, the existence of methylation in the mitochondrial genome is still widely debated. This controversy has been attributed to structural differences between the nuclear and mitochondrial genomes, and to the techniques used to study methylation of cytosines, which were rather optimized for the study of nuclear DNA. However, novel studies suggest that cytosine methylation is truly existing in mitochondria, and that it is mostly found in a non-CpG context, just like in their evolutionary relative, the bacteria.
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Affiliation(s)
- Émélie Leroux
- Département de sciences biologiques, Université de Montréal, Campus MIL, Faculté des Arts et des Sciences, CP 6128, Succursale Centre-Ville, Montréal QC, H3C 3J7, Canada
| | - Cindy Brosseau
- Département de sciences biologiques, Université de Montréal, Campus MIL, Faculté des Arts et des Sciences, CP 6128, Succursale Centre-Ville, Montréal QC, H3C 3J7, Canada
| | - Bernard Angers
- Département de sciences biologiques, Université de Montréal, Campus MIL, Faculté des Arts et des Sciences, CP 6128, Succursale Centre-Ville, Montréal QC, H3C 3J7, Canada
| | - Annie Angers
- Département de sciences biologiques, Université de Montréal, Campus MIL, Faculté des Arts et des Sciences, CP 6128, Succursale Centre-Ville, Montréal QC, H3C 3J7, Canada
| | - Sophie Breton
- Département de sciences biologiques, Université de Montréal, Campus MIL, Faculté des Arts et des Sciences, CP 6128, Succursale Centre-Ville, Montréal QC, H3C 3J7, Canada
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56
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Yamazoe M, Sasano T, Ihara K, Takahashi K, Nakamura W, Takahashi N, Komuro H, Hamada S, Furukawa T. Sparsely methylated mitochondrial cell free DNA released from cardiomyocytes contributes to systemic inflammatory response accompanied by atrial fibrillation. Sci Rep 2021; 11:5837. [PMID: 33737532 PMCID: PMC7973420 DOI: 10.1038/s41598-021-85204-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 02/22/2021] [Indexed: 01/05/2023] Open
Abstract
Systemic inflammation is assumed to be the consequence and the cause of atrial fibrillation (AF); however, the underlying mechanism remains unclear. We aimed to evaluate the level of cell-free DNA (cfDNA) in patients with AF and AF mimicking models, and to illuminate its impact on inflammation. Peripheral blood was obtained from 54 patients with AF and 104 non-AF controls, and cfDNA was extracted. We extracted total cfDNA from conditioned medium after rapid pacing to HL-1 cells. Nuclear and mitochondrial DNA were separately extracted and fragmented to simulate nuclear-cfDNA (n-cfDNA) and mitochondrial-cfDNA (mt-cfDNA). The AF group showed higher cfDNA concentration than the non-AF group (12.6 [9.0–17.1] vs. 8.1 [5.3–10.8] [ng/mL], p < 0.001). The copy numbers of n-cfDNA and mt-cfDNA were higher in AF groups than in non-AF groups; the difference of mt-cfDNA was particularly apparent (p = 0.011 and p < 0.001, respectively). Administration of total cfDNA and mt-cfDNA to macrophages significantly promoted IL-1β and IL-6 expression through TLR9, whereas n-cfDNA did not. Induction of cytokine expression by methylated mt-cfDNA was lower than that by unmethylated mt-cfDNA. Collectively, AF was associated with an increased cfDNA level, especially mt-cfDNA. Sparsely methylated mt-cfDNA released from cardiomyocytes may be involved in sterile systemic inflammation accompanied by AF.
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Affiliation(s)
- Masahiro Yamazoe
- Department of Bio-Informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.,Department of Cardiovascular Physiology, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Tetsuo Sasano
- Department of Cardiovascular Physiology, Tokyo Medical and Dental University (TMDU), Tokyo, Japan. .,Department of Cardiovascular Medicine, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
| | - Kensuke Ihara
- Department of Bio-Informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kentaro Takahashi
- Department of Bio-Informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Wakana Nakamura
- Department of Cardiovascular Physiology, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Naomi Takahashi
- Department of Cardiovascular Physiology, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Hiroaki Komuro
- Department of Cardiovascular Physiology, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Satomi Hamada
- Department of Cardiovascular Physiology, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Tetsushi Furukawa
- Department of Bio-Informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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57
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Snyder RJ, Kleeberger SR. Role of Mitochondrial DNA in Inflammatory Airway Diseases. Compr Physiol 2021; 11:1485-1499. [PMID: 33577124 DOI: 10.1002/cphy.c200010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mitochondrial genome is a small, circular, and highly conserved piece of DNA which encodes only 13 protein subunits yet is vital for electron transport in the mitochondrion and, therefore, vital for the existence of multicellular life on Earth. Despite this importance, mitochondrial DNA (mtDNA) is located in one of the least-protected areas of the cell, exposing it to high concentrations of intracellular reactive oxygen species (ROS) and threat from exogenous substances and pathogens. Until recently, the quality control mechanisms which ensured the stability of the nuclear genome were thought to be minimal or nonexistent in the mitochondria, and the thousands of redundant copies of mtDNA in each cell were believed to be the primary mechanism of protecting these genes. However, a vast network of mechanisms has been discovered that repair mtDNA lesions, replace and recycle mitochondrial chromosomes, and conduct alternate RNA processing for previously undescribed mitochondrial proteins. New mtDNA/RNA-dependent signaling pathways reveal a mostly undiscovered biochemical landscape in which the mitochondria interface with their host cells/organisms. As the myriad ways in which the function of the mitochondrial genome can affect human health have become increasingly apparent, the use of mitogenomic biomarkers (such as copy number and heteroplasmy) as toxicological endpoints has become more widely accepted. In this article, we examine several pathologies of human airway epithelium, including particle exposures, inflammatory diseases, and hyperoxia, and discuss the role of mitochondrial genotoxicity in the pathogenesis and/or exacerbation of these conditions. © 2021 American Physiological Society. Compr Physiol 11:1485-1499, 2021.
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Affiliation(s)
- Ryan J Snyder
- National Institute of Environmental Health Sciences, NIH, Durham, North Carolina, USA
| | - Steven R Kleeberger
- National Institute of Environmental Health Sciences, NIH, Durham, North Carolina, USA
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58
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Small L, Ingerslev LR, Manitta E, Laker RC, Hansen AN, Deeney B, Carrié A, Couvert P, Barrès R. Ablation of DNA-methyltransferase 3A in skeletal muscle does not affect energy metabolism or exercise capacity. PLoS Genet 2021; 17:e1009325. [PMID: 33513138 PMCID: PMC7875352 DOI: 10.1371/journal.pgen.1009325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 02/10/2021] [Accepted: 01/04/2021] [Indexed: 02/03/2023] Open
Abstract
In response to physical exercise and diet, skeletal muscle adapts to energetic demands through large transcriptional changes. This remodelling is associated with changes in skeletal muscle DNA methylation which may participate in the metabolic adaptation to extracellular stimuli. Yet, the mechanisms by which muscle-borne DNA methylation machinery responds to diet and exercise and impacts muscle function are unknown. Here, we investigated the function of de novo DNA methylation in fully differentiated skeletal muscle. We generated muscle-specific DNA methyltransferase 3A (DNMT3A) knockout mice (mD3AKO) and investigated the impact of DNMT3A ablation on skeletal muscle DNA methylation, exercise capacity and energy metabolism. Loss of DNMT3A reduced DNA methylation in skeletal muscle over multiple genomic contexts and altered the transcription of genes known to be influenced by DNA methylation, but did not affect exercise capacity and whole-body energy metabolism compared to wild type mice. Loss of DNMT3A did not alter skeletal muscle mitochondrial function or the transcriptional response to exercise however did influence the expression of genes involved in muscle development. These data suggest that DNMT3A does not have a large role in the function of mature skeletal muscle although a role in muscle development and differentiation is likely. Skeletal muscle is a plastic tissue able to adapt to environmental stimuli such as exercise and diet in order to respond to energetic demand. One of the ways in which skeletal muscle can rapidly react to these stimuli is DNA methylation. This is when chemical groups are attached to DNA, potentially influencing the transcription of genes. We investigated the function of DNA methylation in skeletal muscle by generating mice that lacked one of the main enzymes responsible for de novo DNA methylation, DNA methyltransferase 3A (DNMT3A), specifically in muscle. We found that loss of DNMT3A reduced DNA methylation in muscle however this did not lead to differences in exercise capacity or energy metabolism. This suggests that DNMT3a is not involved in the adaptation of skeletal muscle to diet or exercise.
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Affiliation(s)
- Lewin Small
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars R. Ingerslev
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eleonora Manitta
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rhianna C. Laker
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ann N. Hansen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Brendan Deeney
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alain Carrié
- Sorbonne Université-INSERM UMR_S 1166 ICAN, Pitié-Salpêtrière Hospital, Paris, France
| | - Philippe Couvert
- Sorbonne Université-INSERM UMR_S 1166 ICAN, Pitié-Salpêtrière Hospital, Paris, France
| | - Romain Barrès
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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59
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Immunological mechanisms and therapeutic targets of fatty liver diseases. Cell Mol Immunol 2020; 18:73-91. [PMID: 33268887 PMCID: PMC7852578 DOI: 10.1038/s41423-020-00579-3] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are the two major types of chronic liver disease worldwide. Inflammatory processes play key roles in the pathogeneses of fatty liver diseases, and continuous inflammation promotes the progression of alcoholic steatohepatitis (ASH) and nonalcoholic steatohepatitis (NASH). Although both ALD and NAFLD are closely related to inflammation, their respective developmental mechanisms differ to some extent. Here, we review the roles of multiple immunological mechanisms and therapeutic targets related to the inflammation associated with fatty liver diseases and the differences in the progression of ASH and NASH. Multiple cell types in the liver, including macrophages, neutrophils, other immune cell types and hepatocytes, are involved in fatty liver disease inflammation. In addition, microRNAs (miRNAs), extracellular vesicles (EVs), and complement also contribute to the inflammatory process, as does intertissue crosstalk between the liver and the intestine, adipose tissue, and the nervous system. We point out that inflammation also plays important roles in promoting liver repair and controlling bacterial infections. Understanding the complex regulatory process of disrupted homeostasis during the development of fatty liver diseases may lead to the development of improved targeted therapeutic intervention strategies.
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60
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F C Lopes A. Mitochondrial metabolism and DNA methylation: a review of the interaction between two genomes. Clin Epigenetics 2020; 12:182. [PMID: 33228792 PMCID: PMC7684747 DOI: 10.1186/s13148-020-00976-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/10/2020] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are controlled by the coordination of two genomes: the mitochondrial and the nuclear DNA. As such, variations in nuclear gene expression as a consequence of mutations and epigenetic modifications can affect mitochondrial functionality. Conversely, the opposite could also be true. However, the relationship between mitochondrial dysfunction and epigenetics, such as nuclear DNA methylation, remains largely unexplored.
Mitochondria function as central metabolic hubs controlling some of the main substrates involved in nuclear DNA methylation, via the one carbon metabolism, the tricarboxylic acid cycle and the methionine pathway. Here, we review key findings and highlight new areas of focus, with the ultimate goal of getting one step closer to understanding the genomic effects of mitochondrial dysfunction on nuclear epigenetic landscapes.
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Affiliation(s)
- Amanda F C Lopes
- Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0QQ, UK. .,Medical Research Council - Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge, CB2 0XY, UK.
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61
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MacDonald KM, Benguerfi S, Harding SM. Alerting the immune system to DNA damage: micronuclei as mediators. Essays Biochem 2020; 64:753-764. [PMID: 32844183 PMCID: PMC7588664 DOI: 10.1042/ebc20200016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 08/01/2020] [Accepted: 08/13/2020] [Indexed: 12/18/2022]
Abstract
Healthy cells experience thousands of DNA lesions per day during normal cellular metabolism, and ionizing radiation and chemotherapeutic drugs rely on DNA damage to kill cancer cells. In response to such lesions, the DNA damage response (DDR) activates cell-cycle checkpoints, initiates DNA repair mechanisms, or promotes the clearance of irreparable cells. Work over the past decade has revealed broader influences of the DDR, involving inflammatory gene expression following unresolved DNA damage, and immune surveillance of damaged or mutated cells. Subcellular structures called micronuclei, containing broken fragments of DNA or whole chromosomes that have been isolated away from the rest of the genome, are now recognized as one mediator of DDR-associated immune recognition. Micronuclei can initiate pro-inflammatory signaling cascades, or massively degrade to invoke distinct forms of genomic instability. In this mini-review, we aim to provide an overview of the current evidence linking the DDR to activation of the immune response through micronuclei formation, identifying key areas of interest, open questions, and emerging implications.
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Affiliation(s)
- Kate M MacDonald
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Soraya Benguerfi
- Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada
| | - Shane M Harding
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada
- Department of Radiation Oncology and Immunology, University of Toronto, Toronto, ON, Canada
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62
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Stewart JB, Chinnery PF. Extreme heterogeneity of human mitochondrial DNA from organelles to populations. Nat Rev Genet 2020; 22:106-118. [PMID: 32989265 DOI: 10.1038/s41576-020-00284-x] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2020] [Indexed: 02/06/2023]
Abstract
Contrary to the long-held view that most humans harbour only identical mitochondrial genomes, deep resequencing has uncovered unanticipated extreme genetic variation within mitochondrial DNA (mtDNA). Most, if not all, humans contain multiple mtDNA genotypes (heteroplasmy); specific patterns of variants accumulate in different tissues, including cancers, over time; and some variants are preferentially passed down or suppressed in the maternal germ line. These findings cast light on the origin and spread of mtDNA mutations at multiple scales, from the organelle to the human population, and challenge the conventional view that high percentages of a mutation are required before a new variant has functional consequences.
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Affiliation(s)
- James B Stewart
- Max Planck Institute for Biology of Ageing, Cologne, Germany.,Wellcome Centre for Mitochondrial Research, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Patrick F Chinnery
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
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63
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Bordoni L, Gabbianelli R. Mitochondrial DNA and Neurodegeneration: Any Role for Dietary Antioxidants? Antioxidants (Basel) 2020; 9:E764. [PMID: 32824558 PMCID: PMC7466149 DOI: 10.3390/antiox9080764] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/07/2020] [Accepted: 08/14/2020] [Indexed: 02/07/2023] Open
Abstract
The maintenance of the mitochondrial function is essential in preventing and counteracting neurodegeneration. In particular, mitochondria of neuronal cells play a pivotal role in sustaining the high energetic metabolism of these cells and are especially prone to oxidative damage. Since overproduction of reactive oxygen species (ROS) is involved in the pathogenesis of neurodegeneration, dietary antioxidants have been suggested to counteract the detrimental effects of ROS and to preserve the mitochondrial function, thus slowing the progression and limiting the extent of neuronal cell loss in neurodegenerative disorders. In addition to their role in the redox-system homeostasis, mitochondria are unique organelles in that they contain their own genome (mtDNA), which acts at the interface between environmental exposures and the molecular triggers of neurodegeneration. Indeed, it has been demonstrated that mtDNA (including both genetics and, from recent evidence, epigenetics) might play relevant roles in modulating the risk for neurodegenerative disorders. This mini-review describes the link between the mitochondrial genome and cellular oxidative status, with a particular focus on neurodegeneration; moreover, it provides an overview on potential beneficial effects of antioxidants in preserving mitochondrial functions through the protection of mtDNA.
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Affiliation(s)
- Laura Bordoni
- Unit of Molecular Biology, School of Pharmacy, University of Camerino, 62032 Camerino, Italy;
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64
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Wiese M, Bannister AJ. Two genomes, one cell: Mitochondrial-nuclear coordination via epigenetic pathways. Mol Metab 2020; 38:100942. [PMID: 32217072 PMCID: PMC7300384 DOI: 10.1016/j.molmet.2020.01.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Virtually all eukaryotic cells contain spatially distinct genomes, a single nuclear genome that harbours the vast majority of genes and much smaller genomes found in mitochondria present at thousands of copies per cell. To generate a coordinated gene response to various environmental cues, the genomes must communicate with each another. Much of this bi-directional crosstalk relies on epigenetic processes, including DNA, RNA, and histone modification pathways. Crucially, these pathways, in turn depend on many metabolites generated in specific pools throughout the cell, including the mitochondria. They also involve the transport of metabolites as well as the enzymes that catalyse these modifications between nuclear and mitochondrial genomes. SCOPE OF REVIEW This study examines some of the molecular mechanisms by which metabolites influence the activity of epigenetic enzymes, ultimately affecting gene regulation in response to metabolic cues. We particularly focus on the subcellular localisation of metabolite pools and the crosstalk between mitochondrial and nuclear proteins and RNAs. We consider aspects of mitochondrial-nuclear communication involving histone proteins, and potentially their epigenetic marks, and discuss how nuclear-encoded enzymes regulate mitochondrial function through epitranscriptomic pathways involving various classes of RNA molecules within mitochondria. MAJOR CONCLUSIONS Epigenetic communication between nuclear and mitochondrial genomes occurs at multiple levels, ultimately ensuring a coordinated gene expression response between different genetic environments. Metabolic changes stimulated, for example, by environmental factors, such as diet or physical activity, alter the relative abundances of various metabolites, thereby directly affecting the epigenetic machinery. These pathways, coupled to regulated protein and RNA transport mechanisms, underpin the coordinated gene expression response. Their overall importance to the fitness of a cell is highlighted by the identification of many mutations in the pathways we discuss that have been linked to human disease including cancer.
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Affiliation(s)
- Meike Wiese
- Max-Planck-Institute for Immunobiology und Epigenetics, Department of Chromatin Regulation, Stübeweg 51, 79108, Freiburg im Breisgau, Germany
| | - Andrew J Bannister
- Gurdon Institute and Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK.
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65
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Mitochondrial DNA methylation misleads global DNA methylation detected by antibody-based methods. Anal Biochem 2020; 601:113789. [PMID: 32473121 DOI: 10.1016/j.ab.2020.113789] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/12/2020] [Accepted: 05/17/2020] [Indexed: 12/27/2022]
Abstract
Cytosine methylation is the leading epigenetic modification on DNA playing a role in gene regulation. Methylation can occur in cytosines of any nucleic acids in cytosol (as mitochondrial DNA, mtDNA) and in nuclear DNA (ncDNA). mtDNA exists as multiple copies within numerous mitochondria. This suggests that the number of mitochondria and mtDNA copy number can indicate the presence of a significant amount of DNA methylation within total DNA methylation detected. However, immunofluorescence method does not have a step to discriminate the staining between ncDNA and mtDNA. Antibodies used in immunological methods are methylation-specific but not selective for DNA type and they can bind to methylated cytosines in any DNA within the specimen. Current study aimed to understand whether mtDNA methylation interferes with the detection of nuclear DNA methylation by immunofluorescence and affinity enrichment (ELISA) in different mammalian cells. Experiments were performed to distinguish methylation between mtDNA and ncDNA. Immunofluorescence showed that there was no significant difference in the detected amount of methylation between mitochondrial and nuclear DNA. But ELISA revealed that up to 25% of cellular methylation was derived from mitochondria. This suggests that significant contamination of mtDNA methylation with ncDNA methylation can result in overestimation of the quantitative level of nuclear methylation.
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66
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Vos S, Nawrot TS, Martens DS, Byun HM, Janssen BG. Mitochondrial DNA methylation in placental tissue: a proof of concept study by means of prenatal environmental stressors. Epigenetics 2020; 16:121-131. [PMID: 32657220 PMCID: PMC7889149 DOI: 10.1080/15592294.2020.1790923] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
While previous studies have demonstrated that prenatal exposure to environmental stressors is associated with mitochondrial DNA (mtDNA) methylation, more recent investigations are questioning the accuracy of the methylation assessment and its biological relevance. In this study, we investigated placental mtDNA methylation while accounting for methodological issues such as nuclear contamination, bisulphite conversion, and PCR bias. From the ENVIRONAGE birth cohort, we selected three groups of participants (n = 20/group). One group with mothers who smoked during pregnancy (average 13.2 cig/day), one group with high air pollutant exposure (PM2.5: 16.0 ± 1.4 µg/m3, black carbon: 1.8 ± 0.3 µg/m3) and one control group (non-smokers, PM2.5: 10.6 ± 1.7 µg/m3, black carbon: 0.9 ± 0.1 µg/m3) with low air pollutant exposure. DNA methylation levels were quantified in two regions of the displacement loop control region (D-loop and LDLR2) by bisulphite pyrosequencing. Additionally, we measured DNA methylation on nuclear genes involved in mitochondrial maintenance (PINK1, DNA2, and POLG1) and assessed mtDNA content using qPCR. Absolute D-loop methylation levels were higher for mothers that smoked extensively (+0.36%, 95% CI: 0.06% to 0.66%), and for mothers that were highly exposed to air pollutants (+0.47%, 95% CI: 0.20% to 0.73%). The relevance of our findings is further supported, as D-loop methylation levels were correlated with placental mtDNA content (r = −0.40, p = 0.002) and associated with birth weight (−106.98 g, 95% CI: −209.60 g to −4.36 g for an IQR increase in D-loop methylation). Most notably, our data demonstrates relevant levels of mtDNA methylation in placenta tissue, with significant associations between prenatal exposure to environmental stressors and D-loop methylation.
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Affiliation(s)
- Stijn Vos
- Centre for Environmental Sciences, Hasselt University , Hasselt, Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences, Hasselt University , Hasselt, Belgium.,Department of Public Health & Primary Care, Occupational & Environmental Medicine, Leuven University , Leuven, Belgium
| | - Dries S Martens
- Centre for Environmental Sciences, Hasselt University , Hasselt, Belgium
| | - Hyang-Min Byun
- Population Health Sciences Institute, Newcastle University , Newcastle upon Tyne, UK
| | - Bram G Janssen
- Centre for Environmental Sciences, Hasselt University , Hasselt, Belgium
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Arbeithuber B, Hester J, Cremona MA, Stoler N, Zaidi A, Higgins B, Anthony K, Chiaromonte F, Diaz FJ, Makova KD. Age-related accumulation of de novo mitochondrial mutations in mammalian oocytes and somatic tissues. PLoS Biol 2020; 18:e3000745. [PMID: 32667908 PMCID: PMC7363077 DOI: 10.1371/journal.pbio.3000745] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 05/27/2020] [Indexed: 12/21/2022] Open
Abstract
Mutations create genetic variation for other evolutionary forces to operate on and cause numerous genetic diseases. Nevertheless, how de novo mutations arise remains poorly understood. Progress in the area is hindered by the fact that error rates of conventional sequencing technologies (1 in 100 or 1,000 base pairs) are several orders of magnitude higher than de novo mutation rates (1 in 10,000,000 or 100,000,000 base pairs per generation). Moreover, previous analyses of germline de novo mutations examined pedigrees (and not germ cells) and thus were likely affected by selection. Here, we applied highly accurate duplex sequencing to detect low-frequency, de novo mutations in mitochondrial DNA (mtDNA) directly from oocytes and from somatic tissues (brain and muscle) of 36 mice from two independent pedigrees. We found mtDNA mutation frequencies 2- to 3-fold higher in 10-month-old than in 1-month-old mice, demonstrating mutation accumulation during the period of only 9 mo. Mutation frequencies and patterns differed between germline and somatic tissues and among mtDNA regions, suggestive of distinct mutagenesis mechanisms. Additionally, we discovered a more pronounced genetic drift of mitochondrial genetic variants in the germline of older versus younger mice, arguing for mtDNA turnover during oocyte meiotic arrest. Our study deciphered for the first time the intricacies of germline de novo mutagenesis using duplex sequencing directly in oocytes, which provided unprecedented resolution and minimized selection effects present in pedigree studies. Moreover, our work provides important information about the origins and accumulation of mutations with aging/maturation and has implications for delayed reproduction in modern human societies. Furthermore, the duplex sequencing method we optimized for single cells opens avenues for investigating low-frequency mutations in other studies.
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Affiliation(s)
- Barbara Arbeithuber
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - James Hester
- Department of Animal Science, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Marzia A. Cremona
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Nicholas Stoler
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Arslan Zaidi
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Bonnie Higgins
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Kate Anthony
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Francesca Chiaromonte
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
- EMbeDS, Sant’Anna School of Advanced Studies, Pisa, Italy
| | - Francisco J. Diaz
- Department of Animal Science, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Kateryna D. Makova
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
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68
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Cappa R, de Campos C, Maxwell AP, McKnight AJ. "Mitochondrial Toolbox" - A Review of Online Resources to Explore Mitochondrial Genomics. Front Genet 2020; 11:439. [PMID: 32457801 PMCID: PMC7225359 DOI: 10.3389/fgene.2020.00439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/09/2020] [Indexed: 12/30/2022] Open
Abstract
Mitochondria play a significant role in many biological systems. There is emerging evidence that differences in the mitochondrial genome may contribute to multiple common diseases, leading to an increasing number of studies exploring mitochondrial genomics. There is often a large amount of complex data generated (for example via next generation sequencing), which requires optimised bioinformatics tools to efficiently and effectively generate robust outcomes from these large datasets. Twenty-four online resources dedicated to mitochondrial genomics were reviewed. This 'mitochondrial toolbox' summary resource will enable researchers to rapidly identify the resource(s) most suitable for their needs. These resources fulfil a variety of functions, with some being highly specialised. No single tool will provide all users with the resources they require; therefore, the most suitable tool will vary between users depending on the nature of the work they aim to carry out. Genetics resources are well established for phylogeny and DNA sequence changes, but further epigenetic and gene expression resources need to be developed for mitochondrial genomics.
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Affiliation(s)
- Ruaidhri Cappa
- Centre for Public Health, Institute of Clinical Sciences B, Queen's University Belfast, Royal Victoria Hospital, Belfast, United Kingdom
| | - Cassio de Campos
- School of Electronics, Electrical Engineering and Computer Science, Queen's University Belfast, Belfast, United Kingdom
| | - Alexander P Maxwell
- Centre for Public Health, Institute of Clinical Sciences B, Queen's University Belfast, Royal Victoria Hospital, Belfast, United Kingdom
| | - Amy J McKnight
- Centre for Public Health, Institute of Clinical Sciences B, Queen's University Belfast, Royal Victoria Hospital, Belfast, United Kingdom
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69
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Gyllenhammer LE, Entringer S, Buss C, Wadhwa PD. Developmental programming of mitochondrial biology: a conceptual framework and review. Proc Biol Sci 2020; 287:20192713. [PMID: 32345161 PMCID: PMC7282904 DOI: 10.1098/rspb.2019.2713] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Research on mechanisms underlying the phenomenon of developmental programming of health and disease has focused primarily on processes that are specific to cell types, organs and phenotypes of interest. However, the observation that exposure to suboptimal or adverse developmental conditions concomitantly influences a broad range of phenotypes suggests that these exposures may additionally exert effects through cellular mechanisms that are common, or shared, across these different cell and tissue types. It is in this context that we focus on cellular bioenergetics and propose that mitochondria, bioenergetic and signalling organelles, may represent a key cellular target underlying developmental programming. In this review, we discuss empirical findings in animals and humans that suggest that key structural and functional features of mitochondrial biology exhibit developmental plasticity, and are influenced by the same physiological pathways that are implicated in susceptibility for complex, common age-related disorders, and that these targets of mitochondrial developmental programming exhibit long-term temporal stability. We conclude by articulating current knowledge gaps and propose future research directions to bridge these gaps.
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Affiliation(s)
- Lauren E Gyllenhammer
- Development, Health and Disease Research Program, School of Medicine, Irvine, CA, USA.,Department of Pediatrics, School of Medicine, Irvine, CA, USA
| | - Sonja Entringer
- Development, Health and Disease Research Program, School of Medicine, Irvine, CA, USA.,Department of Pediatrics, School of Medicine, Irvine, CA, USA.,Charité-Universitätsmedizin Berlin, Institute of Medical Psychology, Berlin, Germany
| | - Claudia Buss
- Development, Health and Disease Research Program, School of Medicine, Irvine, CA, USA.,Department of Pediatrics, School of Medicine, Irvine, CA, USA.,Charité-Universitätsmedizin Berlin, Institute of Medical Psychology, Berlin, Germany
| | - Pathik D Wadhwa
- Development, Health and Disease Research Program, School of Medicine, Irvine, CA, USA.,Department of Pediatrics, School of Medicine, Irvine, CA, USA.,Department of Psychiatry and Human Behaviour, School of Medicine, Irvine, CA, USA.,Department of Obstetrics and Gynecology, School of Medicine, Irvine, CA, USA.,Department of Epidemiology, University of California, School of Medicine, Irvine, CA, USA
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70
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Comparative Analysis of CpG Sites and Islands Distributed in Mitochondrial DNA of Model Organisms. Animals (Basel) 2020; 10:ani10040665. [PMID: 32290485 PMCID: PMC7222804 DOI: 10.3390/ani10040665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 02/07/2023] Open
Abstract
Simple Summary In recent years, the existence of methylation of mammalian mitochondrial DNA (mtDNA) has been discussed. The current state of knowledge indicates that mtDNA is poorly methylated; in fact, it only accounts for 2–8% methylated sites and its pattern is unknown. The lack of comprehensive information on the mtDNA methylation pattern prompted us to investigate the distribution of guanine-cytosine-rich sequences (CpG) in different animal species. The aim of the study was to determine the localization of CpG sites and islands in mtDNA of model organisms. The CpG sites and islands found in vertebrates and invertebrates indicate a diversified pattern of CpG distribution. Generally, the number of observed CpG sites of the mitochondrial genome was higher in the analysed vertebrates than in the invertebrates. However, there was no relationship between the frequency of the CpG sites in the mitochondrial genome and the complexity of the analysed organism. The distribution of the CpG sites for transfer RNA (tRNA) coding genes was usually cumulated in a larger CpG region in the vertebrates. Abstract The information about mtDNA methylation is still limited, thus epigenetic modification remains unclear. The lack of comprehensive information on the comparative epigenomics of mtDNA prompts comprehensive investigations of the epigenomic modification of mtDNA in different species. This is the first study in which the theoretical CpG localization in the mtDNA reference sequences from various species (12) was compared. The aim of the study was to determine the localization of CpG sites and islands in mtDNA of model organisms and to compare their distribution. The results are suitable for further investigations of mtDNA methylation. The analysis involved both strands of mtDNA sequences of animal model organisms representing different taxonomic groups of invertebrates and vertebrates. For each sequence, such parameters as the number, length, and localization of CpG islands were determined with the use of EMBOSS (European Molecular Biology Open Software Suite) software. The number of CpG sites for each sequence was indicated using the newcpgseek algorithm. The results showed that methylation of mtDNA in the analysed species involved mitochondrial gene expression. Our analyses showed that the CpG sites were commonly present in genomic regions including the D-loop, CYTB, ND6, ND5, ND4, ND3, ND2, ND1, COX3, COX2, COX1, ATP6, 16s rRNA, and 12s rRNA. The CpG distribution in animals from different species was diversified. Generally, the number of observed CpG sites of the mitochondrial genome was higher in the vertebrates than in the invertebrates. However, there was no relationship between the frequency of the CpG sites in the mitochondrial genome and the complexity of the analysed organisms. Interestingly, the distribution of the CpG sites for tRNA coding genes was usually cumulated in a larger CpG region in vertebrates. This paper may be a starting point for further research, since the collected information indicates possible methylation regions localized in mtDNA among different species including invertebrates and vertebrates.
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71
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Riley JS, Tait SW. Mitochondrial DNA in inflammation and immunity. EMBO Rep 2020; 21:e49799. [PMID: 32202065 PMCID: PMC7132203 DOI: 10.15252/embr.201949799] [Citation(s) in RCA: 434] [Impact Index Per Article: 108.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/31/2020] [Accepted: 03/03/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are cellular organelles that orchestrate a vast range of biological processes, from energy production and metabolism to cell death and inflammation. Despite this seemingly symbiotic relationship, mitochondria harbour within them a potent agonist of innate immunity: their own genome. Release of mitochondrial DNA into the cytoplasm and out into the extracellular milieu activates a plethora of different pattern recognition receptors and innate immune responses, including cGAS‐STING, TLR9 and inflammasome formation leading to, among others, robust type I interferon responses. In this Review, we discuss how mtDNA can be released from the mitochondria, the various inflammatory pathways triggered by mtDNA release and its myriad biological consequences for health and disease.
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Affiliation(s)
- Joel S Riley
- Cancer Research UK Beatson Institute, Glasgow, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Stephen Wg Tait
- Cancer Research UK Beatson Institute, Glasgow, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
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72
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Sharma A, Schaefer ST, Sae-Lee C, Byun HM, Wüllner U. Elevated serum mitochondrial DNA in females and lack of altered platelet mitochondrial methylation in patients with Parkinson´s disease. Int J Neurosci 2020; 131:279-282. [PMID: 32125208 DOI: 10.1080/00207454.2020.1738433] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Purpose: Mitochondrial dysfunction has long been considered in the pathogenesis of Parkinson's disease (PD). This is evident from the presence of mitochondrial DNA deletions in substantia nigra neurons and respiratory chain abnormalities in the skeletal muscle of PD patients. However, the contributing factors that potentially cause oxidative stress in PD are still elusive. To a certain extent, the identification of acquired changes in circulating mitochondrial DNA (mtDNA) content in blood samples may mirror the mitochondrial (dys-) function. Therefore, herein, we investigated the mtDNA concentrations in serum and cerebrospinal fluid (CSF) of PD patients.Materials and methods: We performed quantitative analysis (qPCR) at two mitochondrial regions (D-Loop; ATPase6) and evaluated the platelet mtDNA methylation levels (MT-TL1 ,MT-CO1, MT-CO2 and MT-CO3) by bisulfite-PCR pyrosequencing.Results: Our quantitative analysis at two mitochondrial regions (D-Loop; ATPase6) revealed an increase in mtDNA serum concentrations in PD females compared to healthy females. Of particular interest, these altered concentrations were restricted to females serum only. Thus, in males as well as CSF of PD patients no increase was detected. Additionally, mtDNA methylation in platelets isolated from the plasma of PD patients showed no altered methylation levels in the mitochondrial MT-TL1 and MT-CO1 regions. Besides, a complete lack of platelet mtDNA methylation was observed at MT-CO2 and MT-CO3 mitochondrial sites.Conclusions: Taken together, we found an increased mtDNA serum concentration exclusively in PD females. As of yet, it is unclear whether this might reflect specific changes or characteristics of female PD pathobiology. However, in context to the ongoing debate about mtDNA methylation, we could show that the mitochondrial epigenome does harbor detectable CpG methylation sites in platelets-derived DNA.
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Affiliation(s)
- Amit Sharma
- Department of Neurology, University Clinic Bonn, Bonn, Germany.,Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Simon T Schaefer
- Department of Anesthesiology, University Hospital, LMU Munich, Munich, Germany
| | - Chanachai Sae-Lee
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK.,Research Division, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Hyang-Min Byun
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Ullrich Wüllner
- Department of Neurology, University Clinic Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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73
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Dolinko AH, Chwa M, Atilano SR, Kenney MC. African and Asian Mitochondrial DNA Haplogroups Confer Resistance Against Diabetic Stresses on Retinal Pigment Epithelial Cybrid Cells In Vitro. Mol Neurobiol 2020; 57:1636-1655. [PMID: 31811564 PMCID: PMC7123578 DOI: 10.1007/s12035-019-01834-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 11/12/2019] [Indexed: 01/09/2023]
Abstract
Diabetic retinopathy (DR) is the most common cause of blindness for individuals under the age of 65. This loss of vision can be due to ischemia, neovascularization, and/or diabetic macular edema, which are caused by breakdown of the blood-retina barrier at the level of the retinal pigment epithelium (RPE) and inner retinal vasculature. The prevalence of diabetes and its complications differ between Caucasian-Americans and certain minority populations, such as African-Americans and Asian-Americans. Individuals can be classified by their mitochondrial haplogroups, which are collections of single nucleotide polymorphisms (SNPs) in mitochondrial DNA (mtDNA) representing ancient geographic origins of populations. In this study, we compared the responses of diabetic human RPE cybrids, cell lines containing identical nuclei but mitochondria from either European (maternal European) or maternal African or Asian individuals, to hypoxia and high glucose levels. The African and Asian diabetic ([Afr+Asi]/DM) cybrids showed (1) resistance to both hyperglycemic and hypoxic stresses; (2) downregulation of pro-apoptotic indicator BAX; (3) upregulation of DNA methylation genes, such as DNMT3A and DNMT3B; and (4) resistance to DNA demethylation by the methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-dC) compared to European diabetic (Euro/DM) cybrids. Our findings suggest that mitochondria from African and Asian diabetic subjects possess a "metabolic memory" that confers resistance against hyperglycemia, hypoxia, and demethylation, and that this "metabolic memory" can be transferred into the RPE cybrid cell lines in vitro.
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Affiliation(s)
- Andrew H Dolinko
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, 92697, USA
- Department of Ophthalmology Research, Gavin Herbert Eye Institute, University of California Irvine, Hewitt Hall, Room 2028, 843 Health Science Road, Irvine, CA, 92697, USA
| | - Marilyn Chwa
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - Shari R Atilano
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - M Cristina Kenney
- Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, 92697, USA.
- Department of Ophthalmology Research, Gavin Herbert Eye Institute, University of California Irvine, Hewitt Hall, Room 2028, 843 Health Science Road, Irvine, CA, 92697, USA.
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Heinonen S, Jokinen R, Rissanen A, Pietiläinen KH. White adipose tissue mitochondrial metabolism in health and in obesity. Obes Rev 2020; 21:e12958. [PMID: 31777187 DOI: 10.1111/obr.12958] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
Abstract
White adipose tissue is one of the largest organs of the body. It plays a key role in whole-body energy status and metabolism; it not only stores excess energy but also secretes various hormones and metabolites to regulate body energy balance. Healthy adipose tissue capable of expanding is needed for metabolic well-being and to prevent accumulation of triglycerides to other organs. Mitochondria govern several important functions in the adipose tissue. We review the derangements of mitochondrial function in white adipose tissue in the obese state. Downregulation of mitochondrial function or biogenesis in the white adipose tissue is a central driver for obesity-associated metabolic diseases. Mitochondrial functions compromised in obesity include oxidative functions and renewal and enlargement of the adipose tissue through recruitment and differentiation of adipocyte progenitor cells. These changes adversely affect whole-body metabolic health. Dysfunction of the white adipose tissue mitochondria in obesity has long-term consequences for the metabolism of adipose tissue and the whole body. Understanding the pathways behind mitochondrial dysfunction may help reveal targets for pharmacological or nutritional interventions that enhance mitochondrial biogenesis or function in adipose tissue.
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Affiliation(s)
- Sini Heinonen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Riikka Jokinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Aila Rissanen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Department of Psychiatry, Helsinki University Hospital, Helsinki, Finland
| | - Kirsi H Pietiläinen
- Obesity Research Unit, Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
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75
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Hypermethylation of mitochondrial DNA in vascular smooth muscle cells impairs cell contractility. Cell Death Dis 2020; 11:35. [PMID: 31959742 PMCID: PMC6971246 DOI: 10.1038/s41419-020-2240-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 01/08/2020] [Accepted: 01/08/2020] [Indexed: 01/26/2023]
Abstract
Vascular smooth muscle cell (SMC) from arterial stenotic-occlusive diseases is featured with deficiency in mitochondrial respiration and loss of cell contractility. However, the regulatory mechanism of mitochondrial genes and mitochondrial energy metabolism in SMC remains elusive. Here, we described that DNA methyltransferase 1 (DNMT1) translocated to the mitochondria and catalyzed D-loop methylation of mitochondrial DNA in vascular SMCs in response to platelet-derived growth factor-BB (PDGF-BB). Mitochondrial-specific expression of DNMT1 repressed mitochondrial gene expression, caused functional damage, and reduced SMC contractility. Hypermethylation of mitochondrial D-loop regions were detected in the intima-media layer of mouse carotid arteries subjected to either cessation of blood flow or mechanical endothelial injury, and also in vessel specimens from patients with carotid occlusive diseases. Likewise, the ligated mouse arteries exhibited an enhanced mitochondrial binding of DNMT1, repressed mitochondrial gene expression, defects in mitochondrial respiration, and impaired contractility. The impaired contractility of a ligated vessel could be restored by ex vivo transplantation of DNMT1-deleted mitochondria. In summary, we discovered the function of DNMT1-mediated mitochondrial D-loop methylation in the regulation of mitochondrial gene transcription. Methylation of mitochondrial D-loop in vascular SMCs contributes to impaired mitochondrial function and loss of contractile phenotype in vascular occlusive disease.
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76
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Morris MJ, Hesson LB, Youngson NA. Non-CpG methylation biases bisulphite PCR towards low or unmethylated mitochondrial DNA: recommendations for the field. ENVIRONMENTAL EPIGENETICS 2020; 6:dvaa001. [PMID: 32154030 PMCID: PMC7055202 DOI: 10.1093/eep/dvaa001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 05/04/2023]
Abstract
Mitochondrial DNA (mtDNA) is a circular genome of 16 kb that is present in multiple copies in mitochondria. mtDNA codes for genes that contribute to mitochondrial structure and function. A long-standing question has asked whether mtDNA is epigenetically regulated similarly to the nuclear genome. Recently published data suggest that unlike the nuclear genome where CpG methylation is the norm, mtDNA is methylated predominantly at non-CpG cytosines. This raises important methodological considerations for future investigations. In particular, existing bisulphite PCR techniques may be unsuitable due to primers being biased towards amplification from unmethylated mtDNA. Here, we describe how this may have led to previous studies underestimating the level of mtDNA methylation and reiterate methodological strategies for its accurate assessment.
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Affiliation(s)
| | - Luke B Hesson
- Prince of Wales Clinical School and Lowy Cancer Research Centre, UNSW Sydney, NSW 2052, Australia
| | - Neil A Youngson
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
- The Institute of Hepatology, Foundation for Liver Research, London, SE5 9NT, UK
- Faculty of Life Sciences and Medicine, King’s College London, London, UK
- Correspondence address. The Institute of Hepatology, Foundation for Liver Research, London, UK. Tel : +44 (0)20 7255 9835; E-mail:
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77
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Scarpato R, Testi S, Colosimo V, Garcia Crespo C, Micheli C, Azzarà A, Tozzi MG, Ghirri P. Role of oxidative stress, genome damage and DNA methylation as determinants of pathological conditions in the newborn: an overview from conception to early neonatal stage. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2020; 783:108295. [DOI: 10.1016/j.mrrev.2019.108295] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 11/25/2019] [Accepted: 12/24/2019] [Indexed: 12/15/2022]
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78
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Patil V, Cuenin C, Chung F, Aguilera JR, Fernandez-Jimenez N, Romero-Garmendia I, Bilbao JR, Cahais V, Rothwell J, Herceg Z. Human mitochondrial DNA is extensively methylated in a non-CpG context. Nucleic Acids Res 2019; 47:10072-10085. [PMID: 31665742 PMCID: PMC6821263 DOI: 10.1093/nar/gkz762] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/19/2019] [Accepted: 08/23/2019] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial dysfunction plays critical roles in cancer development and related therapeutic response; however, exact molecular mechanisms remain unclear. Recently, alongside the discovery of mitochondrial-specific DNA methyltransferases, global and site-specific methylation of the mitochondrial genome has been described. Investigation of any functional consequences however remains unclear and debated due to insufficient evidence of the quantitative degree and frequency of mitochondrial DNA (mtDNA) methylation. This study uses WGBS to provide the first quantitative report of mtDNA methylation at single base pair resolution. The data show that mitochondrial genomes are extensively methylated predominantly at non-CpG sites. Importantly, these methylation patterns display notable differences between normal and cancer cells. Furthermore, knockdown of DNA methyltransferase enzymes resulted in a marked global reduction of mtDNA methylation levels, indicating these enzymes may be associated with the establishment and/or maintenance of mtDNA methylation. DNMT3B knockdown cells displayed a comparatively pronounced global reduction in mtDNA methylation with concomitant increases in gene expression, suggesting a potential functional link between methylation and gene expression. Together these results demonstrate reproducible, non-random methylation patterns of mtDNA and challenge the notion that mtDNA is lowly methylated. This study discusses key differences in methodology that suggest future investigations must allow for techniques that assess both CpG and non-CpG methylation.
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Affiliation(s)
- Vibha Patil
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Cyrille Cuenin
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Felicia Chung
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | | | - Nora Fernandez-Jimenez
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Biocruces-Bizkaia Health Research Institute, Leioa, Basque Country 48940, Spain
| | - Irati Romero-Garmendia
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Biocruces-Bizkaia Health Research Institute, Leioa, Basque Country 48940, Spain
| | - Jose Ramon Bilbao
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Biocruces-Bizkaia Health Research Institute, Leioa, Basque Country 48940, Spain
| | - Vincent Cahais
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Joseph Rothwell
- Nutritional Epidemiology Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Zdenko Herceg
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
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79
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Genomic Balance: Two Genomes Establishing Synchrony to Modulate Cellular Fate and Function. Cells 2019; 8:cells8111306. [PMID: 31652817 PMCID: PMC6912345 DOI: 10.3390/cells8111306] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 01/21/2023] Open
Abstract
It is becoming increasingly apparent that cells require cooperation between the nuclear and mitochondrial genomes to promote effective function. However, it was long thought that the mitochondrial genome was under the strict control of the nuclear genome and the mitochondrial genome had little influence on cell fate unless it was extensively mutated, as in the case of the mitochondrial DNA diseases. However, as our understanding of the roles that epigenetic regulators, including DNA methylation, and metabolism play in cell fate and function, the role of the mitochondrial genome appears to have a greater influence than previously thought. In this review, I draw on examples from tumorigenesis, stem cells, and oocyte pre- and post-fertilisation events to discuss how modulating one genome affects the other and that this results in a compromise to produce functional mature cells. I propose that, during development, both of the genomes interact with each other through intermediaries to establish genomic balance and that establishing genomic balance is a key facet in determining cell fate and viability.
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80
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Sharma N, Pasala MS, Prakash A. Mitochondrial DNA: Epigenetics and environment. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:668-682. [PMID: 31335990 PMCID: PMC6941438 DOI: 10.1002/em.22319] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 05/22/2023]
Abstract
Maintenance of the mitochondrial genome is essential for proper cellular function. For this purpose, mitochondrial DNA (mtDNA) needs to be faithfully replicated, transcribed, translated, and repaired in the face of constant onslaught from endogenous and environmental agents. Although only 13 polypeptides are encoded within mtDNA, the mitochondrial proteome comprises over 1500 proteins that are encoded by nuclear genes and translocated to the mitochondria for the purpose of maintaining mitochondrial function. Regulation of mtDNA and mitochondrial proteins by epigenetic changes and post-translational modifications facilitate crosstalk between the nucleus and the mitochondria and ultimately lead to the maintenance of cellular health and homeostasis. DNA methyl transferases have been identified in the mitochondria implicating that methylation occurs within this organelle; however, the extent to which mtDNA is methylated has been debated for many years. Mechanisms of demethylation within this organelle have also been postulated, but the exact mechanisms and their outcomes is still an active area of research. Mitochondrial dysfunction in the form of altered gene expression and ATP production, resulting from epigenetic changes, can lead to various conditions including aging-related neurodegenerative disorders, altered metabolism, changes in circadian rhythm, and cancer. Here, we provide an overview of the epigenetic regulation of mtDNA via methylation, long and short noncoding RNAs, and post-translational modifications of nucleoid proteins (as mitochondria lack histones). We also highlight the influence of xenobiotics such as airborne environmental pollutants, contamination from heavy metals, and therapeutic drugs on mtDNA methylation. Environ. Mol. Mutagen., 60:668-682, 2019. © 2019 Wiley Periodicals, Inc.
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81
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Dou X, Boyd-Kirkup JD, McDermott J, Zhang X, Li F, Rong B, Zhang R, Miao B, Chen P, Cheng H, Xue J, Bennett D, Wong J, Lan F, Han JDJ. The strand-biased mitochondrial DNA methylome and its regulation by DNMT3A. Genome Res 2019; 29:1622-1634. [PMID: 31537639 PMCID: PMC6771398 DOI: 10.1101/gr.234021.117] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 08/23/2019] [Indexed: 01/19/2023]
Abstract
How individual genes are regulated from a mitochondrial polycistronic transcript to have variable expression remains an enigma. Here, through bisulfite sequencing and strand-specific mapping, we show mitochondrial genomes in humans and other animals are strongly biased to light (L)-strand non-CpG methylation with conserved peak loci preferentially located at gene-gene boundaries, which was also independently validated by MeDIP and FspEI digestion. Such mtDNA methylation patterns are conserved across different species and developmental stages but display dynamic local or global changes during development and aging. Knockout of DNMT3A alone perturbed mtDNA regional methylation patterns, but not global levels, and altered mitochondrial gene expression, copy number, and oxygen respiration. Overexpression of DNMT3A strongly increased mtDNA methylation and strand bias. Overall, methylation at gene bodies and boundaries was negatively associated with mitochondrial transcript abundance and also polycistronic transcript processing. Furthermore, HPLC-MS confirmed the methylation signals on mitochondria DNA. Together, these data provide high-resolution mtDNA methylation maps that revealed a strand-specific non-CpG methylation, its dynamic regulation, and its impact on the polycistronic mitochondrial transcript processing.
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Affiliation(s)
- Xiaoyang Dou
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jerome D Boyd-Kirkup
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Joseph McDermott
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiaoli Zhang
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Center for Quantitative Biology (CQB), Peking University, Beijing 100871, China
| | - Fang Li
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Bowen Rong
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Key Laboratory of Epigenetics, Shanghai Ministry of Education, and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Rui Zhang
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Bisi Miao
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Key Laboratory of Epigenetics, Shanghai Ministry of Education, and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Peilin Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Hao Cheng
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jianhuang Xue
- The State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - David Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois 60612, USA
| | - Jiemin Wong
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Fei Lan
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Key Laboratory of Epigenetics, Shanghai Ministry of Education, and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Jing-Dong J Han
- Key Laboratory of Computational Biology, CAS Center for Excellence in Molecular Cell Science, Collaborative Innovation Center for Genetics and Developmental Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Center for Quantitative Biology (CQB), Peking University, Beijing 100871, China
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82
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Mäkinen H, Viitaniemi HM, Visser ME, Verhagen I, van Oers K, Husby A. Temporally replicated DNA methylation patterns in great tit using reduced representation bisulfite sequencing. Sci Data 2019; 6:136. [PMID: 31341168 PMCID: PMC6656709 DOI: 10.1038/s41597-019-0136-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 06/19/2019] [Indexed: 12/28/2022] Open
Abstract
Seasonal timing of reproduction is an important fitness trait in many plants and animals but the underlying molecular mechanism for this trait is poorly known. DNA methylation is known to affect timing of reproduction in various organisms and is therefore a potential mechanism also in birds. Here we describe genome wide data aiming to detect temporal changes in methylation in relation to timing of breeding using artificial selection lines of great tits (Parus major) exposed to contrasting temperature treatments. Methylation levels of DNA extracted from erythrocytes were examined using reduced representation bisulfite sequencing (RRBS). In total, we obtained sequencing data from 63 libraries over four different time points from 16 birds with on average 20 million quality filtered reads per library. These data describe individual level temporal variation in DNA methylation throughout the breeding season under experimental temperature regimes and provides a resource for future studies investigating the role of temporal changes in DNA methylation in timing of reproduction.
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Affiliation(s)
- Hannu Mäkinen
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland.
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
- Centre for Biodiversity Dynamics, Department of Biology, NTNU, Trondheim, Norway.
| | - Heidi M Viitaniemi
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Irene Verhagen
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Arild Husby
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland.
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
- Centre for Biodiversity Dynamics, Department of Biology, NTNU, Trondheim, Norway.
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83
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Patel TH, Norman L, Chang S, Abedi S, Liu C, Chwa M, Atilano SR, Thaker K, Lu S, Jazwinski SM, Miceli MV, Udar N, Bota D, Kenney MC. European mtDNA Variants Are Associated With Differential Responses to Cisplatin, an Anticancer Drug: Implications for Drug Resistance and Side Effects. Front Oncol 2019; 9:640. [PMID: 31380278 PMCID: PMC6659439 DOI: 10.3389/fonc.2019.00640] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 07/01/2019] [Indexed: 01/02/2023] Open
Abstract
Background: Cisplatin, a powerful antitumor agent, causes formation of DNA adducts, and activation of apoptotic pathways. Presently, cisplatin resistance develops in up to 70% of patients but the underlying molecular mechanism(s) are unclear and there are no markers to determine which patients will become resistant. Mitochondria play a significant role not only in energy metabolism but also retrograde signaling (mitochondria to nucleus) that modulates inflammation, complement, and apoptosis pathways. Maternally inherited mitochondrial (mt) DNA can be classified into haplogroups representing different ethnic populations that have diverse susceptibilities to diseases and medications. Methods: Transmitochondrial cybrids, where all cell lines possess identical nuclear genomes but either the H (Southern European) or J (Northern European) mtDNA haplogroups, were treated with cisplatin and analyzed for differential responses related to viability, oxidative stress, and expression levels of genes associated with cancer, cisplatin-induced nephrotoxicity and resistance, apoptosis and signaling pathways. Results: The cisplatin-treated-J cybrids showed greater loss of cell viability along with lower levels of reactive oxygen species and mitochondrial membrane potential compared to cisplatin-treated-H cybrids. After cisplatin treatment, J cybrids showed increased gene expression of BAX, CASP3, and CYP51A, but lower levels of SFRP1 compared to untreated-J cybrids. The cisplatin-treated-H cybrids had elevated expression of CDKN1A/P21, which has a role in cisplatin toxicity, compared to untreated-H cybrids. The cisplatin-treated H had higher transcription levels of ABCC1, DHRS2/HEP27, and EFEMP1 compared to cisplatin-treated-J cybrids. Conclusions: Cybrid cell lines that contain identical nuclei but either H mtDNA mitochondria or J mtDNA mitochondria respond differently to cisplatin treatments suggesting involvement of the retrograde signaling (from mitochondria to nucleus) in the drug-induced cell death. Varying toxicities and transcription levels of the H vs. J cybrids after cisplatin treatment support the hypothesis that mtDNA variants play a role in the expression of genes affecting resistance and side effects of cisplatin.
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Affiliation(s)
- Tej H Patel
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Lucas Norman
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Steven Chang
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Sina Abedi
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Catherine Liu
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States.,Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, IL, United States
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Shari R Atilano
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Kunal Thaker
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Stephanie Lu
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States.,VA Medical Center Long Beach Hospital, Long Beach, CA, United States
| | - S Michal Jazwinski
- Tulane Center for Aging and Department of Medicine, Tulane University, New Orleans, LA, United States
| | - Michael V Miceli
- Tulane Center for Aging and Department of Medicine, Tulane University, New Orleans, LA, United States
| | - Nitin Udar
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Daniela Bota
- Department of Neurology, Neuro-Oncology Division, University of California, Irvine, Irvine, CA, United States
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States.,Department of Pathology and Laboratory Medicine, University of California, Irvine, Irvine, CA, United States
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84
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Sinton MC, Hay DC, Drake AJ. Metabolic control of gene transcription in non-alcoholic fatty liver disease: the role of the epigenome. Clin Epigenetics 2019; 11:104. [PMID: 31319896 PMCID: PMC6637519 DOI: 10.1186/s13148-019-0702-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 07/09/2019] [Indexed: 01/30/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is estimated to affect 24% of the global adult population. NAFLD is a major risk factor for the development of cirrhosis and hepatocellular carcinoma, as well as being strongly associated with type 2 diabetes and cardiovascular disease. It has been proposed that up to 88% of obese adults have NAFLD, and with global obesity rates increasing, this disease is set to become even more prevalent. Despite intense research in this field, the molecular processes underlying the pathology of NAFLD remain poorly understood. Hepatic intracellular lipid accumulation may lead to dysregulated tricarboxylic acid (TCA) cycle activity and associated alterations in metabolite levels. The TCA cycle metabolites alpha-ketoglutarate, succinate and fumarate are allosteric regulators of the alpha-ketoglutarate-dependent dioxygenase family of enzymes. The enzymes within this family have multiple targets, including DNA and chromatin, and thus may be capable of modulating gene transcription in response to intracellular lipid accumulation through alteration of the epigenome. In this review, we discuss what is currently understood in the field and suggest areas for future research which may lead to the development of novel preventative or therapeutic interventions for NAFLD.
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Affiliation(s)
- Matthew C Sinton
- University/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - David C Hay
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK
| | - Amanda J Drake
- University/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.
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85
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Zhou L, Ng HK, Drautz-Moses DI, Schuster SC, Beck S, Kim C, Chambers JC, Loh M. Systematic evaluation of library preparation methods and sequencing platforms for high-throughput whole genome bisulfite sequencing. Sci Rep 2019; 9:10383. [PMID: 31316107 PMCID: PMC6637168 DOI: 10.1038/s41598-019-46875-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 07/05/2019] [Indexed: 01/30/2023] Open
Abstract
Whole genome bisulfite sequencing (WGBS), with its ability to interrogate methylation status at single CpG site resolution epigenome-wide, is a powerful technique for use in molecular experiments. Here, we aim to advance strategies for accurate and efficient WGBS for application in future large-scale epidemiological studies. We systematically compared the performance of three WGBS library preparation methods with low DNA input requirement (Swift Biosciences Accel-NGS, Illumina TruSeq and QIAGEN QIAseq) on two state-of-the-art sequencing platforms (Illumina NovaSeq and HiSeq X), and also assessed concordance between data generated by WGBS and methylation arrays. Swift achieved the highest proportion of CpG sites assayed and effective coverage at 26x (P < 0.001). TruSeq suffered from the highest proportion of PCR duplicates, while QIAseq failed to deliver across all quality metrics. There was little difference in performance between NovaSeq and HiSeq X, with the exception of higher read duplication rate on the NovaSeq (P < 0.05), likely attributable to the higher cluster densities on its flow cells. Systematic biases exist between WGBS and methylation arrays, with lower precision observed for WGBS across the range of depths investigated. To achieve a level of precision broadly comparable to the methylation array, a minimum coverage of 100x is recommended.
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Affiliation(s)
- Li Zhou
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Hong Kiat Ng
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Daniela I Drautz-Moses
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - Stephan C Schuster
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 637551, Singapore
| | - Stephan Beck
- University College London Cancer Institute, London, WC1E 6BT, United Kingdom
| | | | - John Campbell Chambers
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
- Department of Epidemiology and Biostatistics, Imperial College London, London, W2 1PG, United Kingdom
- Department of Cardiology, Ealing Hospital, London North West Healthcare NHS Trust, Southall, UB1 3HW, United Kingdom
- Imperial College Healthcare NHS Trust, London, W12 0HS, United Kingdom
| | - Marie Loh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
- Department of Epidemiology and Biostatistics, Imperial College London, London, W2 1PG, United Kingdom.
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research (A*STAR), Singapore, 138648, Singapore.
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86
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Fila M, Pawłowska E, Blasiak J. Mitochondria in migraine pathophysiology - does epigenetics play a role? Arch Med Sci 2019; 15:944-956. [PMID: 31360189 PMCID: PMC6657237 DOI: 10.5114/aoms.2019.86061] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/06/2018] [Indexed: 12/15/2022] Open
Abstract
The approximately three times higher rate of migraine prevalence in women than men may result from the mitochondrial transmission of this disease. Studies with imaging techniques suggest disturbances in mitochondrial metabolism in specific regions of the brain in migraine patients. Migraine shares some clinical features with several mitochondrial diseases and many other disorders include migraine headaches. Epigenetic regulation of mitochondrial DNA (mtDNA) is a matter of debate and there are some conflicting results, especially on mtDNA methylation. Micro RNAs (miRNAs) and long-noncoding RNA (lncRNAs) have been detected in mitochondria. The regulation of the miRNA-lncRNA axis can be important for mitochondrial physiology and its impairment can result in a disease phenotype. Further studies on the role of mitochondrial epigenetic modifications in migraine are needed, but they require new methods and approaches.
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Affiliation(s)
- Michał Fila
- Department of Neurology, Polish Mother Memorial Hospital, Research Institute, Lodz, Poland
| | | | - Janusz Blasiak
- Department of Molecular Genetics, University of Lodz, Lodz, Poland
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87
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Duan JE, Jiang ZC, Alqahtani F, Mandoiu I, Dong H, Zheng X, Marjani SL, Chen J, Tian XC. Methylome Dynamics of Bovine Gametes and in vivo Early Embryos. Front Genet 2019; 10:512. [PMID: 31191619 PMCID: PMC6546829 DOI: 10.3389/fgene.2019.00512] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/10/2019] [Indexed: 01/12/2023] Open
Abstract
DNA methylation undergoes drastic fluctuation during early mammalian embryogenesis. The dynamics of global DNA methylation in bovine embryos, however, have mostly been studied by immunostaining. We adopted the whole genome bisulfite sequencing (WGBS) method to characterize stage-specific genome-wide DNA methylation in bovine sperm, immature oocytes, oocytes matured in vivo and in vitro, as well as in vivo developed single embryos at the 2-, 4-, 8-, and 16-cell stages. We found that the major wave of genome-wide DNA demethylation was complete by the 8-cell stage when de novo methylation became prominent. Sperm and oocytes were differentially methylated in numerous regions (DMRs), which were primarily intergenic, suggesting that these non-coding regions may play important roles in gamete specification. DMRs were also identified between in vivo and in vitro matured oocytes, suggesting environmental effects on epigenetic modifications. In addition, virtually no (less than 1.5%) DNA methylation was found in mitochondrial DNA. Finally, by using RNA-seq data generated from embryos at the same developmental stages, we revealed a weak inverse correlation between gene expression and promoter methylation. This comprehensive analysis provides insight into the critical features of the bovine embryo methylome, and serves as an important reference for embryos produced in vitro, such as by in vitro fertilization and cloning. Lastly, these data can also provide a model for the epigenetic dynamics in human early embryos.
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Affiliation(s)
- Jingyue Ellie Duan
- Department of Animal Science, University of Connecticut, Storrs, CT, United States
| | - Zongliang Carl Jiang
- School of Animal Science, AgCenter, Louisiana State University, Baton Rouge, LA, United States
| | - Fahad Alqahtani
- Department of Computer Science and Engineering, University of Connecticut, Storrs, CT, United States
| | - Ion Mandoiu
- Department of Computer Science and Engineering, University of Connecticut, Storrs, CT, United States
| | - Hong Dong
- Institute of Animal Science, Xinjiang Academy of Animal Sciences, Ürümqi, China
| | - Xinbao Zheng
- Institute of Animal Science, Xinjiang Academy of Animal Sciences, Ürümqi, China
| | - Sadie L Marjani
- Department of Biology, Central Connecticut State University, New Britain, CT, United States
| | - Jingbo Chen
- Institute of Animal Science, Xinjiang Academy of Animal Sciences, Ürümqi, China
| | - Xiuchun Cindy Tian
- Department of Animal Science, University of Connecticut, Storrs, CT, United States
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88
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Dhiman H, Gerstl MP, Ruckerbauer D, Hanscho M, Himmelbauer H, Clarke C, Barron N, Zanghellini J, Borth N. Genetic and Epigenetic Variation across Genes Involved in Energy Metabolism and Mitochondria of Chinese Hamster Ovary Cell Lines. Biotechnol J 2019; 14:e1800681. [DOI: 10.1002/biot.201800681] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 03/14/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Heena Dhiman
- Department of BiotechnologyUniversity of Natural Resources and Life SciencesVienna Austria
- Austrian Centre of Industrial BiotechnologyMuthgasse 11 1190 Vienna Austria
| | - Matthias P. Gerstl
- Department of BiotechnologyUniversity of Natural Resources and Life SciencesVienna Austria
- Austrian Centre of Industrial BiotechnologyMuthgasse 11 1190 Vienna Austria
| | - David Ruckerbauer
- Austrian Centre of Industrial BiotechnologyMuthgasse 11 1190 Vienna Austria
| | - Michael Hanscho
- Austrian Centre of Industrial BiotechnologyMuthgasse 11 1190 Vienna Austria
| | - Heinz Himmelbauer
- Department of BiotechnologyUniversity of Natural Resources and Life SciencesVienna Austria
| | - Colin Clarke
- National Institute for Bioprocessing Research and TrainingBlackrock, Co Dublin Ireland
| | - Niall Barron
- National Institute for Bioprocessing Research and TrainingBlackrock, Co Dublin Ireland
- School of Chemical and Bioprocess EngineeringUniversity College DublinGlasnevin Whitehall Dublin Ireland
| | - Jürgen Zanghellini
- Austrian Centre of Industrial BiotechnologyMuthgasse 11 1190 Vienna Austria
- Austrian Biotech University of Applied SciencesKonrad Lorenz Strasse 10 3430 Tulln Austria
| | - Nicole Borth
- Department of BiotechnologyUniversity of Natural Resources and Life SciencesVienna Austria
- Austrian Centre of Industrial BiotechnologyMuthgasse 11 1190 Vienna Austria
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89
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Dostal V, Churchill MEA. Cytosine methylation of mitochondrial DNA at CpG sequences impacts transcription factor A DNA binding and transcription. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2019; 1862:598-607. [PMID: 30807854 PMCID: PMC7806247 DOI: 10.1016/j.bbagrm.2019.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/21/2019] [Accepted: 01/23/2019] [Indexed: 12/22/2022]
Abstract
In eukaryotes, cytosine methylation of nuclear DNA at CpG sequences (5mCpG) regulates epigenetic inheritance through alterations in chromatin structure. However, mitochondria lack nucleosomal chromatin, therefore the molecular mechanisms by which 5mCpG influences mitochondria must be different and are as yet unknown. Mitochondrial Transcription Factor A (TFAM) is both the primary DNA-compacting protein in the mitochondrial DNA (mtDNA) nucleoid and a transcription-initiation factor. TFAM must encounter hundreds of CpGs in mtDNA, so the occurrence of 5mCpG has the potential to impact TFAM-DNA recognition. We used biophysical approaches to determine whether 5mCpG alters any TFAM-dependent activities. 5mCpG in the heavy strand promoter (HSP1) increased the binding affinity of TFAM and induced TFAM multimerization with increased cooperativity compared to nonmethylated DNA. However, 5mCpG had no apparent effect on TFAM-dependent DNA compaction. Additionally, 5mCpG had a clear and context-dependent effect on transcription initiating from the three mitochondrial promoters. Taken together, our findings demonstrate that 5mCpG in the mitochondrial promoter region does impact TFAM-dependent activities in vitro.
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Affiliation(s)
- Vishantie Dostal
- Program in Structural Biology and Biochemistry, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mair E A Churchill
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Program in Structural Biology and Biochemistry, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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90
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Lapp HE, Bartlett AA, Hunter RG. Stress and glucocorticoid receptor regulation of mitochondrial gene expression. J Mol Endocrinol 2019; 62:R121-R128. [PMID: 30082335 DOI: 10.1530/jme-18-0152] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/06/2018] [Indexed: 01/05/2023]
Abstract
Glucocorticoids have long been recognized for their role in regulating the availability of energetic resources, particularly during stress. Furthermore, bidirectional connections between glucocorticoids and the physiology and function of mitochondria have been discovered over the years. However, the precise mechanisms by which glucocorticoids act on mitochondria have only recently been explored. Glucocorticoids appear to regulate mitochondrial transcription via activation of glucocorticoid receptors (GRs) with elevated circulating glucocorticoid levels following stress. While several mechanistic questions remain, GR and other nuclear transcription factors appear to have the capacity to substantially alter mitochondrial transcript abundance. The regulation of mitochondrial transcripts by stress and glucocorticoids will likely prove functionally relevant in many stress-sensitive tissues including the brain.
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91
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Chocron ES, Munkácsy E, Pickering AM. Cause or casualty: The role of mitochondrial DNA in aging and age-associated disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:285-297. [PMID: 30419337 PMCID: PMC6310633 DOI: 10.1016/j.bbadis.2018.09.035] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/20/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022]
Abstract
The mitochondrial genome (mtDNA) represents a tiny fraction of the whole genome, comprising just 16.6 kilobases encoding 37 genes involved in oxidative phosphorylation and the mitochondrial translation machinery. Despite its small size, much interest has developed in recent years regarding the role of mtDNA as a determinant of both aging and age-associated diseases. A number of studies have presented compelling evidence for key roles of mtDNA in age-related pathology, although many are correlative rather than demonstrating cause. In this review we will evaluate the evidence supporting and opposing a role for mtDNA in age-associated functional declines and diseases. We provide an overview of mtDNA biology, damage and repair as well as the influence of mitochondrial haplogroups, epigenetics and maternal inheritance in aging and longevity.
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Affiliation(s)
- E Sandra Chocron
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA
| | - Erin Munkácsy
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA
| | - Andrew M Pickering
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA; Department of Molecular Medicine, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245-3207, USA.
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92
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Fan S, Tian T, Chen W, Lv X, Lei X, Zhang H, Sun S, Cai L, Pan G, He L, Ou Z, Lin X, Wang X, Perez MF, Tu Z, Ferrone S, Tannous BA, Li J. Mitochondrial miRNA Determines Chemoresistance by Reprogramming Metabolism and Regulating Mitochondrial Transcription. Cancer Res 2019; 79:1069-1084. [PMID: 30659020 DOI: 10.1158/0008-5472.can-18-2505] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 11/01/2018] [Accepted: 01/10/2019] [Indexed: 11/16/2022]
MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Apoptosis
- Argonaute Proteins/genetics
- Argonaute Proteins/metabolism
- Biomarkers, Tumor
- Carcinoma, Squamous Cell/drug therapy
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Nucleus/genetics
- Cell Nucleus/metabolism
- Cell Proliferation
- Cellular Reprogramming
- Cisplatin/pharmacology
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/metabolism
- Drug Resistance, Neoplasm/genetics
- Follow-Up Studies
- Gene Expression Regulation, Neoplastic
- Genome, Mitochondrial
- Humans
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Mitochondria/genetics
- Mitochondria/metabolism
- Oxidative Phosphorylation
- Prognosis
- Retrospective Studies
- Survival Rate
- Tongue Neoplasms/drug therapy
- Tongue Neoplasms/genetics
- Tongue Neoplasms/metabolism
- Tongue Neoplasms/pathology
- Transcription, Genetic
- Tumor Cells, Cultured
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Song Fan
- Department of Oral and Maxillofacial Surgery, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tian Tian
- Department of Neurobiology, Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Weixiong Chen
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Xiaobin Lv
- Markey Cancer Center, The University of Kentucky, College of Medicine, Lexington, Kentucky
- Nanchang Key Laboratory of Cancer Pathogenesis and Translational Research, Center Laboratory, the Third Affiliated Hospital, Nanchang University, Nanchang, China
| | - Xinyuan Lei
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Hanqing Zhang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Sheng Sun
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, Massachusetts
| | - Lei Cai
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Guokai Pan
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Lile He
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Zhanpeng Ou
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Xinyu Lin
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
| | - Xinhui Wang
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Matthew Francis Perez
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Zhiming Tu
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Bakhos A Tannous
- Experimental Therapeutics and Molecular Imaging Lab, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Jinsong Li
- Department of Oral and Maxillofacial Surgery, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China.
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation of Sun Yat-Sen Memorial Hospital, Guangzhou, China
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93
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Abstract
Marine organisms' persistence hinges on the capacity for acclimatization and adaptation to the myriad of interacting environmental stressors associated with global climate change. In this context, epigenetics-mechanisms that facilitate phenotypic variation through genotype-environment interactions-are of great interest ecologically and evolutionarily. Our comprehensive review of marine environmental epigenetics guides our recommendations of four key areas for future research: the dynamics of wash-in and wash-out of epigenetic effects, the mechanistic understanding of the interplay of different epigenetic marks and the interaction with the microbiome, the capacity for and mechanisms of transgenerational epigenetic inheritance, and the evolutionary implications of the interaction of genetic and epigenetic features. Emerging insights in marine environmental epigenetics can be applied to critical issues such as aquaculture, biomonitoring, and biological invasions, thereby improving our ability to explain and predict the responses of marine taxa to global climate change.
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Affiliation(s)
- Jose M Eirin-Lopez
- Environmental Epigenetics Laboratory, Center for Coastal Oceans Research, Institute for Water and Environment, Florida International University, North Miami, Florida 33181, USA;
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island 02881, USA;
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94
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Kim JI, Lee SY, Park M, Kim SY, Kim JW, Kim SA, Kim BN. Peripheral Mitochondrial DNA Copy Number is Increased in Korean Attention-Deficit Hyperactivity Disorder Patients. Front Psychiatry 2019; 10:506. [PMID: 31379624 PMCID: PMC6656858 DOI: 10.3389/fpsyt.2019.00506] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 06/27/2019] [Indexed: 01/10/2023] Open
Abstract
The involvement of mitochondrial dysfunction in the pathophysiology of attention-deficit hyperactivity disorder (ADHD) has been suggested in several reports. Mitochondrial DNA (mtDNA) copy number as well as methylation of the D-loop region and peroxisome-proliferator-activated receptor γ co-activator-1α (PPARGC1A) are considered biomarkers for mitochondrial dysfunction. We compared the mtDNA copy number and methylation ratio of the D-loop region and PPARGC1A between ADHD patients and controls and also among ADHD subtypes. The present study included 70 subjects with ADHD and 70 age- and gender-matched healthy controls (HCs). We measured the relative mtDNA copy number in peripheral blood cells using quantitative polymerase chain reaction (qPCR), and the methylation ratio was measured using methylation-specific PCR (MSP) after bisulfite conversion. The relative mtDNA copy number was significantly higher in ADHD patients than in HCs (p = 0.028). The mtDNA methylation ratio of PPARGC1A was decreased in ADHD patients compared with HCs (p = 0.008). After adjusting for IQ level, only the mtDNA copy number differed between the ADHD and HCs (p = 0.01). There was a significant difference in the methylation ratio of PPARGC1A among ADHD subtypes. These results suggest the possible involvement of mitochondrial dysfunction in the pathophysiology of ADHD. Further large cohort studies investigating the correlation between clinical markers and biomarkers of mitochondrial dysfunction are warranted.
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Affiliation(s)
- Johanna Inhyang Kim
- Department of Psychiatry, Hanyang University Medical Center, Seoul, South Korea
| | - Soo-Young Lee
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, South Korea
| | - Mira Park
- Department of Preventive Medicine, School of Medicine, Eulji University, Daejeon, South Korea
| | - Si Yeon Kim
- Department of Preventive Medicine, School of Medicine, Eulji University, Daejeon, South Korea
| | - Jae-Won Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea
| | - Soon Ae Kim
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, South Korea
| | - Bung-Nyun Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea
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95
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Coppedè F, Stoccoro A. Mitoepigenetics and Neurodegenerative Diseases. Front Endocrinol (Lausanne) 2019; 10:86. [PMID: 30837953 PMCID: PMC6389613 DOI: 10.3389/fendo.2019.00086] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial impairment and increased oxidative stress are common features in neurodegenerative disorders, leading researchers to speculate that epigenetic changes in the mitochondrial DNA (mitoepigenetics) could contribute to neurodegeneration. The few studies performed so far to address this issue revealed impaired methylation levels of the mitochondrial regulatory region (D-loop region) in both animal models, postmortem brain regions, or circulating blood cells of patients with Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Those studies also revealed that mtDNA D-loop methylation levels are subjected to a dynamic regulation within the progression of the neurodegenerative process, could be affected by certain neurodegenerative disease-causative mutations, and are inversely correlated with the mtDNA copy number. The methylation levels of other mtDNA regions than the D-loop have been scarcely investigated in human specimens from patients with neurodegenerative disorders or in animal models of the disease, and evidence of impaired methylation levels is often limited to a single study, making it difficult to clarify their correlation with mitochondrial dynamics and gene expression levels in these disorders. Overall, the preliminary results of the studies performed so far are encouraging making mitoepigenetics a timely and attractive field of investigation, but additional research is warranted to clarify the connections among epigenetic changes occurring in the mitochondrial genome, mitochondrial DNA dynamics and gene expression, and the neurodegenerative process.
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96
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Morris MJ, Hesson LB, Poulos RC, Ward RL, Wong JWH, Youngson NA. Reduced nuclear DNA methylation and mitochondrial transcript changes in adenomas do not associate with mtDNA methylation. Biomark Res 2018; 6:37. [PMID: 30619609 PMCID: PMC6311003 DOI: 10.1186/s40364-018-0151-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 11/28/2018] [Indexed: 12/15/2022] Open
Abstract
Background Altered mitochondrial function and large-scale changes to DNA methylation patterns in the nuclear genome are both hallmarks of colorectal cancer (CRC). Mitochondria have multiple copies of a 16 kb circular genome that contains genes that are vital for their function. While DNA methylation is known to alter the nuclear genome in CRC, it is not clear whether it could have a similar influence in mtDNA; indeed, currently, the issue of whether mitochondrial genome (mtDNA) methylation occurs is controversial. Thus our goal here was to determine whether the methylation state of mtDNA is linked to mitochondrial gene transcription in colorectal adenomas, and to assess its suitability as a biomarker in CRC. Methods To investigate the relationship between DNA methylation and mitochondrial transcripts in adenomas, we performed RNA-sequencing and Whole Genome Bisulphite Sequencing (WGBS) of mtDNA-enriched DNA from normal mucosa and paired adenoma patient samples. Results Transcriptional profiling indicated that adenomas had reduced mitochondrial proton transport versus normal mucosa, consistent with altered mitochondrial function. The expression of 3 tRNAs that are transcribed from mtDNA were also decreased in adenoma. Overall methylation of CG dinucleotides in the nuclear genome was reduced in adenomas (68%) compared to normal mucosa (75%, P < 0.01). Methylation in mtDNA was low (1%) in both normal and adenoma tissue but we observed clusters of higher methylation at the ribosomal RNA genes. Levels of methylation within these regions did not differ between normal and adenoma tissue. Conclusions We provide evidence that low-level methylation of specific sites does exist in the mitochondrial genome but that it is not associated with mitochondrial gene transcription changes in adenomas. Furthermore, as no large scale changes to mtDNA methylation were observed it is unlikely to be a suitable biomarker for early-stage CRC. Electronic supplementary material The online version of this article (10.1186/s40364-018-0151-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M J Morris
- 1Department of Pharmacology, School of Medical Sciences, UNSW Sydney, Sydney, NSW Australia
| | - L B Hesson
- 2Prince of Wales Clinical School and Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW Australia
| | - R C Poulos
- 2Prince of Wales Clinical School and Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW Australia.,3Children's Medical Research Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, NSW Australia
| | - R L Ward
- 2Prince of Wales Clinical School and Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW Australia.,4Office of the Deputy Vice-Chancellor (Research), University of Queensland, QLD, Brisbane, Australia
| | - J W H Wong
- 2Prince of Wales Clinical School and Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW Australia.,5School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong, Special Administrative Region of China
| | - N A Youngson
- 1Department of Pharmacology, School of Medical Sciences, UNSW Sydney, Sydney, NSW Australia
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97
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Sun X, Vaghjiani V, Jayasekara WSN, Cain JE, St John JC. The degree of mitochondrial DNA methylation in tumor models of glioblastoma and osteosarcoma. Clin Epigenetics 2018; 10:157. [PMID: 30558637 PMCID: PMC6296150 DOI: 10.1186/s13148-018-0590-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/21/2018] [Indexed: 12/16/2022] Open
Abstract
Background Different cell types possess different copies of mtDNA to support their specific requirements for cellular metabolism. Cell-specific mtDNA copy numbers are established through cell-specific mtDNA replication during cell differentiation. However, cancer cells are trapped in a “pseudo-differentiated” state as they fail to expand mtDNA copy number. Global DNA methylation can regulate this process, as induced DNA demethylation promotes differentiation of cancer cells and expansion of mtDNA copy number. Results To determine the role that mtDNA methylation plays in regulating mtDNA replication during tumorigenesis, we have characterized the patterns of mtDNA methylation using glioblastoma and osteosarcoma tumor models that have different combinations of mtDNA genotypes and copy number against common nuclear genome backgrounds at different stages of tumor progression. To ensure the reliability of the findings, we have applied a robust experimental pipeline including three approaches, namely whole-mtDNA bisulfite-sequencing with mtDNA-genotype-specific analysis, pyrosequencing, and methylated immunoprecipitation against 5mC and 5hmC. We have determined genotype-specific methylation profiles, which were modulated through tumor progression. Moreover, a strong influence from the nuclear genome was also observed on mtDNA methylation patterns using the same mtDNA genotype under different nuclear genomes. Furthermore, the numbers of mtDNA copy in tumor-initiating cells affected mtDNA methylation levels in late-stage tumors. Conclusions Our findings highlight the influences that the nuclear and mitochondrial genomes have in setting mtDNA methylation patterns to regulate mtDNA copy number in tumorigenesis. They have important implications for assessing global DNA methylation patterns in tumorigenesis and the availability of mtDNA template for mtDNA replication. Electronic supplementary material The online version of this article (10.1186/s13148-018-0590-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xin Sun
- Mitochondrial Genetics Group, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia.,Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 27-31 Wright Street, Clayton, VIC, 3168, Australia
| | - Vijesh Vaghjiani
- Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 27-31 Wright Street, Clayton, VIC, 3168, Australia.,Centre for Cancer Research, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia
| | - W Samantha N Jayasekara
- Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 27-31 Wright Street, Clayton, VIC, 3168, Australia.,Centre for Cancer Research, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia
| | - Jason E Cain
- Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 27-31 Wright Street, Clayton, VIC, 3168, Australia.,Centre for Cancer Research, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia
| | - Justin C St John
- Mitochondrial Genetics Group, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, VIC, 3168, Australia. .,Department of Molecular and Translational Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, 27-31 Wright Street, Clayton, VIC, 3168, Australia.
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98
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Baulch JE. Radiation-induced genomic instability, epigenetic mechanisms and the mitochondria: a dysfunctional ménage a trois? Int J Radiat Biol 2018; 95:516-525. [DOI: 10.1080/09553002.2018.1549757] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Janet E. Baulch
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA
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99
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Jeltsch A, Broche J, Bashtrykov P. Molecular Processes Connecting DNA Methylation Patterns with DNA Methyltransferases and Histone Modifications in Mammalian Genomes. Genes (Basel) 2018; 9:genes9110566. [PMID: 30469440 PMCID: PMC6266221 DOI: 10.3390/genes9110566] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 12/20/2022] Open
Abstract
DNA methylation is an essential part of the epigenome chromatin modification network, which also comprises several covalent histone protein post-translational modifications. All these modifications are highly interconnected, because the writers and erasers of one mark, DNA methyltransferases (DNMTs) and ten eleven translocation enzymes (TETs) in the case of DNA methylation, are directly or indirectly targeted and regulated by other marks. Here, we have collected information about the genomic distribution and variability of DNA methylation in human and mouse DNA in different genomic elements. After summarizing the impact of DNA methylation on genome evolution including CpG depletion, we describe the connection of DNA methylation with several important histone post-translational modifications, including methylation of H3K4, H3K9, H3K27, and H3K36, but also with nucleosome remodeling. Moreover, we present the mechanistic features of mammalian DNA methyltransferases and their associated factors that mediate the crosstalk between DNA methylation and chromatin modifications. Finally, we describe recent advances regarding the methylation of non-CpG sites, methylation of adenine residues in human cells and methylation of mitochondrial DNA. At several places, we highlight controversial findings or open questions demanding future experimental work.
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Affiliation(s)
- Albert Jeltsch
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany.
| | - Julian Broche
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany.
| | - Pavel Bashtrykov
- Institute of Biochemistry and Technical Biochemistry, Department of Biochemistry, University of Stuttgart, 70569 Stuttgart, Germany.
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Mechta M, Ingerslev LR, Barrès R. Methodology for Accurate Detection of Mitochondrial DNA Methylation. J Vis Exp 2018:57772. [PMID: 29863674 PMCID: PMC6101301 DOI: 10.3791/57772] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Quantification of DNA methylation can be achieved using bisulfite sequencing, which takes advantage of the property of sodium bisulfite to convert unmethylated cytosine into uracil, in a single-stranded DNA context. Bisulfite sequencing can be targeted (using PCR) or performed on the whole genome and provides absolute quantification of cytosine methylation at the single base-resolution. Given the distinct nature of nuclear- and mitochondrial DNA, notably in the secondary structure, adaptions of bisulfite sequencing methods for investigating cytosine methylation in mtDNA should be made. Secondary and tertiary structure of mtDNA can indeed lead to bisulfite sequencing artifacts leading to false-positives due to incomplete denaturation poor access of bisulfite to single-stranded DNA. Here, we describe a protocol using an enzymatic digestion of DNA with BamHI coupled with bioinformatic analysis pipeline to allow accurate quantification of cytosine methylation levels in mtDNA. In addition, we provide guidelines for designing the bisulfite sequencing primers specific to mtDNA, in order to avoid targeting undesirable NUclear MiTochondrial segments (NUMTs) inserted into the nuclear genome.
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Affiliation(s)
- Mie Mechta
- The Novo Nordisk Foundation for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen
| | - Lars Roed Ingerslev
- The Novo Nordisk Foundation for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen
| | - Romain Barrès
- The Novo Nordisk Foundation for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen;
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