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England E, Morris JW, Bussy C, Hancox JC, Shiels HA. The key characteristics of cardiotoxicity for the pervasive pollutant phenanthrene. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:133853. [PMID: 38503207 DOI: 10.1016/j.jhazmat.2024.133853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/08/2024] [Accepted: 02/19/2024] [Indexed: 03/21/2024]
Abstract
The key characteristic (KCs) framework has been used previously to assess the carcinogenicity and cardiotoxicity of various chemical and pharmacological agents. Here, the 12 KCs of cardiotoxicity are used to evaluate the previously reported cardiotoxicity of phenanthrene (Phe), a tricyclic polycyclic aromatic hydrocarbon (PAH), and major component of fossil fuel-derived air pollution. Phe is a semi-volatile pollutant existing in both the gas phase and particle phase through adsorption onto or into particulate matter (PM). Phe can translocate across the airways and gastrointestinal tract into the systemic circulation, enabling body-wide effects. Our evaluation based on a comprehensive literature review, indicates Phe exhibits 11 of the 12 KCs for cardiotoxicity. These include adverse effects on cardiac electromechanical performance, the vasculature and endothelium, immunomodulation and oxidative stress, and neuronal and endocrine control. Environmental agents that have similarly damaging effects on the cardiovascular system are heavily regulated and monitored, yet globally there is no air quality regulation specific for PAHs like Phe. Environmental monitoring of Phe is not the international standard with benzo[a]pyrene being frequently used as a proxy despite the two PAH species exhibiting significant differences in sources, concentration variations and toxic effects. The evidence summarised in this evaluation highlights the need to move away from proxied PAH measurements and develop a monitoring network capable of measuring Phe concentration. It also stresses the need to raise awareness amongst the medical community of the potential cardiovascular impact of PAH exposure. This will allow the production of mitigation strategies and possibly the development of new policies for the protection of the societal groups most vulnerable to cardiovascular disease.
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Affiliation(s)
- E England
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
| | - J W Morris
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
| | - C Bussy
- Division of Immunology, Immunity to Infection, and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - J C Hancox
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - H A Shiels
- Division of Cardiovascular Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
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2
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Kozal JS, Jayasundara N, Massarsky A, Lindberg CD, Oliveri AN, Cooper EM, Levin ED, Meyer JN, Giulio RTD. Mitochondrial dysfunction and oxidative stress contribute to cross-generational toxicity of benzo(a)pyrene in Danio rerio. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 263:106658. [PMID: 37722151 PMCID: PMC10591944 DOI: 10.1016/j.aquatox.2023.106658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/06/2023] [Accepted: 08/10/2023] [Indexed: 09/20/2023]
Abstract
The potential for polycyclic aromatic hydrocarbons (PAHs) to have adverse effects that persist across generations is an emerging concern for human and wildlife health. This study evaluated the role of mitochondria, which are maternally inherited, in the cross-generational toxicity of benzo(a)pyrene (BaP), a model PAH and known mitochondrial toxicant. Mature female zebrafish (F0) were fed diets containing 0, 12.5, 125, or 1250 μg BaP/g at a feed rate of 1% body weight twice/day for 21 days. These females were bred with unexposed males, and the embryos (F1) were collected for subsequent analyses. Maternally-exposed embryos exhibited altered mitochondrial function and metabolic partitioning (i.e. the portion of respiration attributable to different cellular processes), as evidenced by in vivo oxygen consumption rates (OCRs). F1 embryos had lower basal and mitochondrial respiration and ATP turnover-mediated OCR, and increased proton leak and reserve capacity. Reductions in mitochondrial DNA (mtDNA) copy number, increases in mtDNA damage, and alterations in biomarkers of oxidative stress were also found in maternally-exposed embryos. Notably, the mitochondrial effects in offspring occurred largely in the absence of effects in maternal ovaries, suggesting that PAH-induced mitochondrial dysfunction may manifest in subsequent generations. Maternally-exposed larvae also displayed swimming hypoactivity. The lowest observed effect level (LOEL) for maternal BaP exposure causing mitochondrial effects in offspring was 12.5 µg BaP/g diet (nominally equivalent to 250 ng BaP/g fish). It was concluded that maternal BaP exposure can cause significant mitochondrial impairments in offspring.
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Affiliation(s)
- Jordan S Kozal
- Nicholas School of the Environment, Duke University, Durham, NC, USA.
| | | | - Andrey Massarsky
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Casey D Lindberg
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Anthony N Oliveri
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
| | - Ellen M Cooper
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Edward D Levin
- Nicholas School of the Environment, Duke University, Durham, NC, USA; Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA; Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC, USA
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3
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Roy A, Kandettu A, Ray S, Chakrabarty S. Mitochondrial DNA replication and repair defects: Clinical phenotypes and therapeutic interventions. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148554. [PMID: 35341749 DOI: 10.1016/j.bbabio.2022.148554] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/06/2022] [Accepted: 03/16/2022] [Indexed: 12/15/2022]
Abstract
Mitochondria is a unique cellular organelle involved in multiple cellular processes and is critical for maintaining cellular homeostasis. This semi-autonomous organelle contains its circular genome - mtDNA (mitochondrial DNA), that undergoes continuous cycles of replication and repair to maintain the mitochondrial genome integrity. The majority of the mitochondrial genes, including mitochondrial replisome and repair genes, are nuclear-encoded. Although the repair machinery of mitochondria is quite efficient, the mitochondrial genome is highly susceptible to oxidative damage and other types of exogenous and endogenous agent-induced DNA damage, due to the absence of protective histones and their proximity to the main ROS production sites. Mutations in replication and repair genes of mitochondria can result in mtDNA depletion and deletions subsequently leading to mitochondrial genome instability. The combined action of mutations and deletions can result in compromised mitochondrial genome maintenance and lead to various mitochondrial disorders. Here, we review the mechanism of mitochondrial DNA replication and repair process, key proteins involved, and their altered function in mitochondrial disorders. The focus of this review will be on the key genes of mitochondrial DNA replication and repair machinery and the clinical phenotypes associated with mutations in these genes.
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Affiliation(s)
- Abhipsa Roy
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Amoolya Kandettu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Swagat Ray
- Department of Life Sciences, School of Life and Environmental Sciences, University of Lincoln, Lincoln LN6 7TS, United Kingdom
| | - Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
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4
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Leuthner TC, Meyer JN. Mitochondrial DNA Mutagenesis: Feature of and Biomarker for Environmental Exposures and Aging. Curr Environ Health Rep 2021; 8:294-308. [PMID: 34761353 PMCID: PMC8826492 DOI: 10.1007/s40572-021-00329-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2021] [Indexed: 01/12/2023]
Abstract
PURPOSE OF REVIEW Mitochondrial dysfunction is a hallmark of aging. Mitochondrial genome (mtDNA) instability contributes to mitochondrial dysfunction, and mtDNA mutagenesis may contribute to aging. However, the origin of mtDNA mutations remains somewhat controversial. The goals of this review are to introduce and review recent literature on mtDNA mutagenesis and aging, address recent animal and epidemiological evidence for the effects of chemicals on mtDNA damage and mutagenesis, propose hypotheses regarding the contribution of environmental toxicant exposure to mtDNA mutagenesis in the context of aging, and suggest future directions and approaches for environmental health researchers. RECENT FINDINGS Stressors such as pollutants, pharmaceuticals, and ultraviolet radiation can damage the mitochondrial genome or disrupt mtDNA replication, repair, and organelle homeostatic processes, potentially influencing the rate of accumulation of mtDNA mutations. Accelerated mtDNA mutagenesis could contribute to aging, diseases of aging, and sensitize individuals with pathogenic mtDNA variants to stressors. We propose three potential mechanisms of toxicant-induced effects on mtDNA mutagenesis over lifespan: (1) increased de novo mtDNA mutations, (2) altered frequencies of mtDNA mutations, or (3) both. There are remarkably few studies that have investigated the impact of environmental chemical exposures on mtDNA instability and mutagenesis, and even fewer in the context of aging. More studies are warranted because people are exposed to tens of thousands of chemicals, and are living longer. Finally, we suggest that toxicant-induced mtDNA damage and mutational signatures may be a sensitive biomarker for some exposures.
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Affiliation(s)
- Tess C Leuthner
- Nicholas School of the Environment, 9 Circuit Dr, Box 90328, Duke University, NC, 27708, USA
| | - Joel N Meyer
- Nicholas School of the Environment, 9 Circuit Dr, Box 90328, Duke University, NC, 27708, USA.
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5
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Hershberger KA, Rooney JP, Turner EA, Donoghue LJ, Bodhicharla R, Maurer LL, Ryde IT, Kim JJ, Joglekar R, Hibshman JD, Smith LL, Bhatt DP, Ilkayeva OR, Hirschey MD, Meyer JN. Early-life mitochondrial DNA damage results in lifelong deficits in energy production mediated by redox signaling in Caenorhabditis elegans. Redox Biol 2021; 43:102000. [PMID: 33993056 PMCID: PMC8134077 DOI: 10.1016/j.redox.2021.102000] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 04/19/2021] [Accepted: 04/28/2021] [Indexed: 11/12/2022] Open
Abstract
The consequences of damage to the mitochondrial genome (mtDNA) are poorly understood, although mtDNA is more susceptible to damage resulting from some genotoxicants than nuclear DNA (nucDNA), and many environmental toxicants target the mitochondria. Reports from the toxicological literature suggest that exposure to early-life mitochondrial damage could lead to deleterious consequences later in life (the “Developmental Origins of Health and Disease” paradigm), but reports from other fields often report beneficial (“mitohormetic”) responses to such damage. Here, we tested the effects of low (causing no change in lifespan) levels of ultraviolet C (UVC)-induced, irreparable mtDNA damage during early development in Caenorhabditis elegans. This exposure led to life-long reductions in mtDNA copy number and steady-state ATP levels, accompanied by increased oxygen consumption and altered metabolite profiles, suggesting inefficient mitochondrial function. Exposed nematodes were also developmentally delayed, reached smaller adult size, and were rendered more susceptible to subsequent exposure to chemical mitotoxicants. Metabolomic and genetic analysis of key signaling and metabolic pathways supported redox and mitochondrial stress-response signaling during early development as a mechanism for establishing these persistent alterations. Our results highlight the importance of early-life exposures to environmental pollutants, especially in the context of exposure to chemicals that target mitochondria. Early life mtDNA damage led to lifelong deficits in mitochondrial function. C. elegans developed slowly and were sensitive to chemical exposures as adults. Redox signaling is a mechanism that establishes these persistent alterations. Data are consistent with the Developmental Origins of Health and Disease model.
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Affiliation(s)
- Kathleen A Hershberger
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - John P Rooney
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Elena A Turner
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Lauren J Donoghue
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Rakesh Bodhicharla
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Laura L Maurer
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Ian T Ryde
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Jina J Kim
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Rashmi Joglekar
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | - Jonathan D Hibshman
- Duke University Department of Biology and University Program in Genetics and Genomics, Durham, NC, USA
| | - Latasha L Smith
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA
| | | | | | | | - Joel N Meyer
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, Durham, NC, USA.
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6
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Sullivan ED, Longley MJ, Copeland WC. Polymerase γ efficiently replicates through many natural template barriers but stalls at the HSP1 quadruplex. J Biol Chem 2021; 295:17802-17815. [PMID: 33454015 DOI: 10.1074/jbc.ra120.015390] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/05/2020] [Indexed: 12/27/2022] Open
Abstract
Faithful replication of the mitochondrial genome is carried out by a set of key nuclear-encoded proteins. DNA polymerase γ is a core component of the mtDNA replisome and the only replicative DNA polymerase localized to mitochondria. The asynchronous mechanism of mtDNA replication predicts that the replication machinery encounters dsDNA and unique physical barriers such as structured genes, G-quadruplexes, and other obstacles. In vitro experiments here provide evidence that the polymerase γ heterotrimer is well-adapted to efficiently synthesize DNA, despite the presence of many naturally occurring roadblocks. However, we identified a specific G-quadruplex-forming sequence at the heavy-strand promoter (HSP1) that has the potential to cause significant stalling of mtDNA replication. Furthermore, this structured region of DNA corresponds to the break site for a large (3,895 bp) deletion observed in mitochondrial disease patients. The presence of this deletion in humans correlates with UV exposure, and we have found that efficiency of polymerase γ DNA synthesis is reduced after this quadruplex is exposed to UV in vitro.
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Affiliation(s)
- Eric D Sullivan
- Mitochondrial DNA Replication Group, Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Matthew J Longley
- Mitochondrial DNA Replication Group, Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - William C Copeland
- Mitochondrial DNA Replication Group, Genome Integrity and Structural Biology Laboratory, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina, USA.
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7
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Raftery TD, Jayasundara N, Di Giulio RT. A bioenergetics assay for studying the effects of environmental stressors on mitochondrial function in vivo in zebrafish larvae. Comp Biochem Physiol C Toxicol Pharmacol 2017; 192:23-32. [PMID: 27939721 PMCID: PMC5218841 DOI: 10.1016/j.cbpc.2016.12.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 12/01/2016] [Accepted: 12/02/2016] [Indexed: 01/29/2023]
Abstract
Mitochondria, an integral component of cellular energy metabolism and other key functions, are extremely vulnerable to damage by environmental stressors. Although methods to measure mitochondrial function in vitro exist, sensitive, medium- to high-throughput assays that assess respiration within physiologically-relevant whole organisms are needed to identify drugs and/or chemicals that disrupt mitochondrial function, particularly at sensitive early developmental stages. Consequently, we have developed and optimized an assay to measure mitochondrial bioenergetics in zebrafish larvae using the XFe24 Extracellular Flux Analyzer. To prevent larval movement from confounding oxygen consumption measurements, we relied on MS-222-based anesthetization. We obtained stable measurement values in the absence of effects on average oxygen consumption rate and subsequently optimized the use of pharmacological agents for metabolic partitioning. To confirm assay reproducibility we demonstrated that triclosan, a positive control, significantly decreased spare respiratory capacity. We then exposed zebrafish from 5 hours post-fertilization (hpf) to 6days post-fertilization (dpf) to three polycyclic aromatic hydrocarbons (PAHs) - benzo(a)pyrene (BaP), phenanthrene (Phe), and fluoranthene (FL) - and measured various fundamental parameters of mitochondrial respiratory chain function, including maximal respiration, spare respiratory capacity, mitochondrial and non-mitochondrial respiration. Exposure to all three PAHs decreased spare respiratory capacity and maximal respiration. Additionally, Phe exposure increased non-mitochondrial respiration and FL exposure decreased mitochondrial respiration and increased non-mitochondrial respiration. Overall, this whole organism-based assay provides a platform for examining mitochondrial dysfunction in vivo at critical developmental stages. It has important implications in biomedical sciences, toxicology and ecophysiology, particularly to examine the effects of environmental chemicals and/or drugs on mitochondrial bioenergetics.
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Affiliation(s)
- Tara D Raftery
- Nicholas School of the Environment, Duke University, Durham, NC 27708, United States.
| | - Nishad Jayasundara
- Nicholas School of the Environment, Duke University, Durham, NC 27708, United States
| | - Richard T Di Giulio
- Nicholas School of the Environment, Duke University, Durham, NC 27708, United States
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8
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Ling X, Zhang G, Sun L, Wang Z, Zou P, Gao J, Peng K, Chen Q, Yang H, Zhou N, Cui Z, Zhou Z, Liu J, Cao J, Ao L. Polycyclic aromatic hydrocarbons exposure decreased sperm mitochondrial DNA copy number: A cross-sectional study (MARHCS) in Chongqing, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 220:680-687. [PMID: 27751638 DOI: 10.1016/j.envpol.2016.10.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/08/2016] [Accepted: 10/09/2016] [Indexed: 06/06/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that have adverse effects on the male reproductive function. Many studies have confirmed that PAHs preferentially accumulate in mitochondria DNA relative to nuclear DNA and disrupt mitochondrial functions. However, it is rare whether exposure to PAHs is associated with mitochondrial damage and dysfunction in sperm. To evaluate the effects of PAHs on sperm mitochondria, we measured mitochondrial membrane potential (MMP), mitochondrial DNA copy number (mtDNAcn) and mtDNA integrity in 666 individuals from the Male Reproductive Health in Chongqing College Students (MARHCS) study. PAHs exposure was estimated by measuring eight urinary PAH metabolites (1-OHNap, 2-OHNap, 1-OHPhe, 2-OHPhe, 3-OHPhe, 4-OHPhe, 2-OHFlu and 1-OHPyr). The subjects were divided into low, median and high exposure groups using the tertile levels of urinary PAH metabolites. In univariate analyses, the results showed that increased levels of 2-OHPhe, 3-OHPhe, ∑Phe metabolites and 2-OHFlu were found to be associated with decreased sperm mtDNAcn. After adjusting for potential confounders, significantly negative associations of these metabolites remained (p = 0.039, 0.012, 0.01, 0.035, respectively). Each 1 μg/g creatinine increase in 2-OHPhe, 3-OHPhe, ∑Phe metabolites and 2-OHFlu was associated with a decrease in sperm mtDNAcn of 9.427%, 11.488%, 9.635% and 11.692%, respectively. There were no significant associations between urinary PAH metabolites and sperm MMP or mtDNA integrity. The results indicated that the low exposure levels of PAHs can cause abnormities in sperm mitochondria.
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Affiliation(s)
- Xi Ling
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Guowei Zhang
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Lei Sun
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Zhi Wang
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Peng Zou
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Jianfang Gao
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Kaige Peng
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Qing Chen
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Huan Yang
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Niya Zhou
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Zhihong Cui
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Ziyuan Zhou
- Department of Environmental Health, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Jinyi Liu
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Jia Cao
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Lin Ao
- Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
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9
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Valente WJ, Ericson NG, Long AS, White PA, Marchetti F, Bielas JH. Mitochondrial DNA exhibits resistance to induced point and deletion mutations. Nucleic Acids Res 2016; 44:8513-8524. [PMID: 27550180 PMCID: PMC5062989 DOI: 10.1093/nar/gkw716] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/04/2016] [Indexed: 12/17/2022] Open
Abstract
The accumulation of somatic mitochondrial DNA (mtDNA) mutations contributes to the pathogenesis of human disease. Currently, mitochondrial mutations are largely considered results of inaccurate processing of its heavily damaged genome. However, mainly from a lack of methods to monitor mtDNA mutations with sufficient sensitivity and accuracy, a link between mtDNA damage and mutation has not been established. To test the hypothesis that mtDNA-damaging agents induce mtDNA mutations, we exposed MutaTMMouse mice to benzo[a]pyrene (B[a]P) or N-ethyl-N-nitrosourea (ENU), daily for 28 consecutive days, and quantified mtDNA point and deletion mutations in bone marrow and liver using our newly developed Digital Random Mutation Capture (dRMC) and Digital Deletion Detection (3D) assays. Surprisingly, our results demonstrate mutagen treatment did not increase mitochondrial point or deletion mutation frequencies, despite evidence both compounds increase nuclear DNA mutations and demonstrated B[a]P adduct formation in mtDNA. These findings contradict models of mtDNA mutagenesis that assert the elevated rate of mtDNA mutation stems from damage sensitivity and abridged repair capacity. Rather, our results demonstrate induced mtDNA damage does not readily convert into mutation. These findings suggest robust mitochondrial damage responses repress induced mutations after mutagen exposure.
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Affiliation(s)
- William J Valente
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA Medical Scientist Training Program, University of Washington School of Medicine, Seattle, WA 98195, USA Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Nolan G Ericson
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Alexandra S Long
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Paul A White
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Jason H Bielas
- Translational Research Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA 98195, USA Department of Pathology, University of Washington, Seattle, WA 98195, USA Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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10
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Van Houten B, Hunter SE, Meyer JN. Mitochondrial DNA damage induced autophagy, cell death, and disease. Front Biosci (Landmark Ed) 2016; 21:42-54. [PMID: 26709760 DOI: 10.2741/4375] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Mammalian mitochondria contain multiple small genomes. While these organelles have efficient base excision removal of oxidative DNA lesions and alkylation damage, many DNA repair systems that work on nuclear DNA damage are not active in mitochondria. What is the fate of DNA damage in the mitochondria that cannot be repaired or that overwhelms the repair system? Some forms of mitochondrial DNA damage can apparently trigger mitochondrial DNA destruction, either via direct degradation or through specific forms of autophagy, such as mitophagy. However, accumulation of certain types of mitochondrial damage, in the absence of DNA ligase III (Lig3) or exonuclease G (EXOG), can directly trigger cell death. This review examines the cellular effects of persistent damage to mitochondrial genomes and discusses the very different cell fates that occur in response to different kinds of damage.
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Affiliation(s)
- Bennett Van Houten
- Department of Pharmacology Chemical Biology, University of Pittsburgh, 15213-1863,
| | - Senyene E Hunter
- School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27516
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC 27708-0328
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11
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Abstract
Mitochondrial DNA is replicated by the nuclear-encoded DNA polymerase γ (pol γ) which is composed of a single 140 kDa catalytic subunit and a dimeric 55 kDa accessory subunit. Mitochondrial DNA is vulnerable to various forms of damage, including several types of oxidative lesions, UV-induced photoproducts, chemical adducts from environmental sources, as well as alkylation and inter-strand cross-links from chemotherapy agents. Although many of these lesions block DNA replication, pol γ can bypass some lesions by nucleotide incorporation opposite a template lesion and further extension of the DNA primer past the lesion. This process of translesion synthesis (TLS) by pol γ can occur in either an error-free or an error-prone manner. Assessment of TLS requires extensive analysis of oligonucleotide substrates and replication products by denaturing polyacrylamide sequencing gels. This chapter presents protocols for the analysis of translesion DNA synthesis.
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12
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Massarsky A, Jayasundara N, Bailey JM, Oliveri AN, Levin ED, Prasad GL, Di Giulio RT. Teratogenic, bioenergetic, and behavioral effects of exposure to total particulate matter on early development of zebrafish (Danio rerio) are not mimicked by nicotine. Neurotoxicol Teratol 2015; 51:77-88. [PMID: 26391568 PMCID: PMC4821439 DOI: 10.1016/j.ntt.2015.09.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/14/2015] [Accepted: 09/17/2015] [Indexed: 10/23/2022]
Abstract
Cigarette smoke has been associated with a number of pathologies; however, the mechanisms leading to developmental effects are yet to be fully understood. The zebrafish embryo is regarded as a 'bridge model'; however, not many studies examined its applicability to cigarette smoke toxicity. This study examined the effects of total particulate matter (TPM) from 3R4F reference cigarettes on the early development of zebrafish (Danio rerio). Zebrafish embryos were exposed to two concentrations of TPM (0.4 and 1.4 μg/mL equi-nicotine units) or nicotine at equivalent doses. The exposures began at 2h post-fertilization (hpf) and lasted until 96 hpf. Several physiological parameters were assessed during or after the exposure. We show that TPM increased mortality, delayed hatching, and increased the incidence of deformities in zebrafish. TPM exposure also increased the incidence of hemorrhage and disrupted the angiogenesis of the major vessels in the brain. Moreover, TPM exposure reduced the larval body length, decreased the heart rate, and reduced the metabolic rate. Biomarkers of xenobiotic metabolism and oxidative stress were also affected. TPM-exposed zebrafish also differed behaviorally: at 24 hpf the embryos had a higher frequency of spontaneous contractions and at 144 hpf the larvae displayed swimming hyperactivity. This study demonstrates that TPM disrupts several aspects of early development in zebrafish. The effects reported for TPM were not attributable to nicotine, since embryos treated with nicotine alone did not differ significantly from the control group. Collectively, our work illustrates the utility of zebrafish as an alternative model to evaluate the toxic effects of cigarette smoke constituents.
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Affiliation(s)
- Andrey Massarsky
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
| | - Nishad Jayasundara
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
| | - Jordan M Bailey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA.
| | - Anthony N Oliveri
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA.
| | - Edward D Levin
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA.
| | - G L Prasad
- R&D Department, R.J. Reynolds Tobacco Company, Winston-Salem, NC 27102, USA.
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13
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Akhmedov AT, Marín-García J. Mitochondrial DNA maintenance: an appraisal. Mol Cell Biochem 2015; 409:283-305. [DOI: 10.1007/s11010-015-2532-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/06/2015] [Indexed: 12/13/2022]
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14
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González-Hunt CP, Leung MCK, Bodhicharla RK, McKeever MG, Arrant AE, Margillo KM, Ryde IT, Cyr DD, Kosmaczewski SG, Hammarlund M, Meyer JN. Exposure to mitochondrial genotoxins and dopaminergic neurodegeneration in Caenorhabditis elegans. PLoS One 2014; 9:e114459. [PMID: 25486066 PMCID: PMC4259338 DOI: 10.1371/journal.pone.0114459] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 10/31/2014] [Indexed: 12/12/2022] Open
Abstract
Neurodegeneration has been correlated with mitochondrial DNA (mtDNA) damage and exposure to environmental toxins, but causation is unclear. We investigated the ability of several known environmental genotoxins and neurotoxins to cause mtDNA damage, mtDNA depletion, and neurodegeneration in Caenorhabditis elegans. We found that paraquat, cadmium chloride and aflatoxin B1 caused more mitochondrial than nuclear DNA damage, and paraquat and aflatoxin B1 also caused dopaminergic neurodegeneration. 6-hydroxydopamine (6-OHDA) caused similar levels of mitochondrial and nuclear DNA damage. To further test whether the neurodegeneration could be attributed to the observed mtDNA damage, C. elegans were exposed to repeated low-dose ultraviolet C radiation (UVC) that resulted in persistent mtDNA damage; this exposure also resulted in dopaminergic neurodegeneration. Damage to GABAergic neurons and pharyngeal muscle cells was not detected. We also found that fasting at the first larval stage was protective in dopaminergic neurons against 6-OHDA-induced neurodegeneration. Finally, we found that dopaminergic neurons in C. elegans are capable of regeneration after laser surgery. Our findings are consistent with a causal role for mitochondrial DNA damage in neurodegeneration, but also support non mtDNA-mediated mechanisms.
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Affiliation(s)
- Claudia P. González-Hunt
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Maxwell C. K. Leung
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Rakesh K. Bodhicharla
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Madeline G. McKeever
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Andrew E. Arrant
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America
| | - Kathleen M. Margillo
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Ian T. Ryde
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
| | - Derek D. Cyr
- Center for Applied Genomics and Technology, Duke University, Durham, North Carolina, United States of America
| | - Sara G. Kosmaczewski
- Department of Genetics, Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Marc Hammarlund
- Department of Genetics, Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Joel N. Meyer
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America
- * E-mail: mailto:
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15
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Abstract
Human mitochondria harbor an essential, high copy number, 16,569 base pair, circular DNA genome that encodes 13 gene products required for electron transport and oxidative phosphorylation. Mutation of this genome can compromise cellular respiration, ultimately resulting in a variety of progressive metabolic diseases collectively known as 'mitochondrial diseases'. Mutagenesis of mtDNA and the persistence of mtDNA mutations in cells and tissues is a complex topic, involving the interplay of DNA replication, DNA damage and repair, purifying selection, organelle dynamics, mitophagy, and aging. We briefly review these general elements that affect maintenance of mtDNA, and we focus on nuclear genes encoding the mtDNA replication machinery that can perturb the genetic integrity of the mitochondrial genome.
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Affiliation(s)
- William C Copeland
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, Durham, NC 27709, USA.
| | - Matthew J Longley
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, Durham, NC 27709, USA
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16
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Meyer JN, Leung MCK, Rooney JP, Sendoel A, Hengartner MO, Kisby GE, Bess AS. Mitochondria as a target of environmental toxicants. Toxicol Sci 2013; 134:1-17. [PMID: 23629515 PMCID: PMC3693132 DOI: 10.1093/toxsci/kft102] [Citation(s) in RCA: 350] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Enormous strides have recently been made in our understanding of the biology and pathobiology of mitochondria. Many diseases have been identified as caused by mitochondrial dysfunction, and many pharmaceuticals have been identified as previously unrecognized mitochondrial toxicants. A much smaller but growing literature indicates that mitochondria are also targeted by environmental pollutants. We briefly review the importance of mitochondrial function and maintenance for health based on the genetics of mitochondrial diseases and the toxicities resulting from pharmaceutical exposure. We then discuss how the principles of mitochondrial vulnerability illustrated by those fields might apply to environmental contaminants, with particular attention to factors that may modulate vulnerability including genetic differences, epigenetic interactions, tissue characteristics, and developmental stage. Finally, we review the literature related to environmental mitochondrial toxicants, with a particular focus on those toxicants that target mitochondrial DNA. We conclude that the fields of environmental toxicology and environmental health should focus more strongly on mitochondria.
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Affiliation(s)
- Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC, USA.
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17
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Kasiviswanathan R, Minko IG, Lloyd RS, Copeland WC. Translesion synthesis past acrolein-derived DNA adducts by human mitochondrial DNA polymerase γ. J Biol Chem 2013; 288:14247-14255. [PMID: 23543747 DOI: 10.1074/jbc.m113.458802] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Acrolein, a mutagenic aldehyde, is produced endogenously by lipid peroxidation and exogenously by combustion of organic materials, including tobacco products. Acrolein reacts with DNA bases forming exocyclic DNA adducts, such as γ-hydroxy-1,N(2)-propano-2'-deoxyguanosine (γ-HOPdG) and γ-hydroxy-1,N(6)-propano-2'-deoxyadenosine (γ-HOPdA). The bulky γ-HOPdG adduct blocks DNA synthesis by replicative polymerases but can be bypassed by translesion synthesis polymerases in the nucleus. Although acrolein-induced adducts are likely to be formed and persist in mitochondrial DNA, animal cell mitochondria lack specialized translesion DNA synthesis polymerases to tolerate these lesions. Thus, it is important to understand how pol γ, the sole mitochondrial DNA polymerase in human cells, acts on acrolein-adducted DNA. To address this question, we investigated the ability of pol γ to bypass the minor groove γ-HOPdG and major groove γ-HOPdA adducts using single nucleotide incorporation and primer extension analyses. The efficiency of pol γ-catalyzed bypass of γ-HOPdG was low, and surprisingly, pol γ preferred to incorporate purine nucleotides opposite the adduct. Pol γ also exhibited ∼2-fold lower rates of excision of the misincorporated purine nucleotides opposite γ-HOPdG compared with the corresponding nucleotides opposite dG. Extension of primers from the termini opposite γ-HOPdG was accomplished only following error-prone purine nucleotide incorporation. However, pol γ preferentially incorporated dT opposite the γ-HOPdA adduct and efficiently extended primers from the correctly paired terminus, indicating that γ-HOPdA is probably nonmutagenic. In summary, our data suggest that acrolein-induced exocyclic DNA lesions can be bypassed by mitochondrial DNA polymerase but, in the case of the minor groove γ-HOPdG adduct, at the cost of unprecedented high mutation rates.
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Affiliation(s)
- Rajesh Kasiviswanathan
- Mitochondrial DNA Replication Group, Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Irina G Minko
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon 97239
| | - R Stephen Lloyd
- Center for Research on Occupational and Environmental Toxicology, Oregon Health and Science University, Portland, Oregon 97239; Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239
| | - William C Copeland
- Mitochondrial DNA Replication Group, Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709.
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18
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Bess AS, Crocker TL, Ryde IT, Meyer JN. Mitochondrial dynamics and autophagy aid in removal of persistent mitochondrial DNA damage in Caenorhabditis elegans. Nucleic Acids Res 2012; 40:7916-31. [PMID: 22718972 PMCID: PMC3439916 DOI: 10.1093/nar/gks532] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mitochondria lack the ability to repair certain helix-distorting lesions that are induced at high levels in mitochondrial DNA (mtDNA) by important environmental genotoxins and endogenous metabolites. These lesions are irreparable and persistent in the short term, but their long-term fate is unknown. We report that removal of such mtDNA damage is detectable by 48 h in Caenorhabditis elegans, and requires mitochondrial fusion, fission and autophagy, providing genetic evidence for a novel mtDNA damage removal pathway. Furthermore, mutations in genes involved in these processes as well as pharmacological inhibition of autophagy exacerbated mtDNA damage-mediated larval arrest, illustrating the in vivo relevance of removal of persistent mtDNA damage. Mutations in genes in these pathways exist in the human population, demonstrating the potential for important gene-environment interactions affecting mitochondrial health after genotoxin exposure.
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Affiliation(s)
- Amanda S Bess
- Duke University, Nicholas School of Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
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19
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Mitochondrial DNA damage and its consequences for mitochondrial gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:979-91. [PMID: 22728831 DOI: 10.1016/j.bbagrm.2012.06.002] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 06/06/2012] [Accepted: 06/14/2012] [Indexed: 12/11/2022]
Abstract
How mitochondria process DNA damage and whether a change in the steady-state level of mitochondrial DNA damage (mtDNA) contributes to mitochondrial dysfunction are questions that fuel burgeoning areas of research into aging and disease pathogenesis. Over the past decade, researchers have identified and measured various forms of endogenous and environmental mtDNA damage and have elucidated mtDNA repair pathways. Interestingly, mitochondria do not appear to contain the full range of DNA repair mechanisms that operate in the nucleus, although mtDNA contains types of damage that are targets of each nuclear DNA repair pathway. The reduced repair capacity may, in part, explain the high mutation frequency of the mitochondrial chromosome. Since mtDNA replication is dependent on transcription, mtDNA damage may alter mitochondrial gene expression at three levels: by causing DNA polymerase γ nucleotide incorporation errors leading to mutations, by interfering with the priming of mtDNA replication by the mitochondrial RNA polymerase, or by inducing transcriptional mutagenesis or premature transcript termination. This review summarizes our current knowledge of mtDNA damage, its repair, and its effects on mtDNA integrity and gene expression. This article is part of a special issue entitled: Mitochondrial Gene Expression.
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20
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Overexpression of DNA polymerase zeta reduces the mitochondrial mutability caused by pathological mutations in DNA polymerase gamma in yeast. PLoS One 2012; 7:e34322. [PMID: 22470557 PMCID: PMC3314619 DOI: 10.1371/journal.pone.0034322] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 02/28/2012] [Indexed: 12/27/2022] Open
Abstract
In yeast, DNA polymerase zeta (Rev3 and Rev7) and Rev1, involved in the error-prone translesion synthesis during replication of nuclear DNA, localize also in mitochondria. We show that overexpression of Rev3 reduced the mtDNA extended mutability caused by a subclass of pathological mutations in Mip1, the yeast mitochondrial DNA polymerase orthologous to human Pol gamma. This beneficial effect was synergistic with the effect achieved by increasing the dNTPs pools. Since overexpression of Rev3 is detrimental for nuclear DNA mutability, we constructed a mutant Rev3 isoform unable to migrate into the nucleus: its overexpression reduced mtDNA mutability without increasing the nuclear one.
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21
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Kasiviswanathan R, Gustafson MA, Copeland WC, Meyer JN. Human mitochondrial DNA polymerase γ exhibits potential for bypass and mutagenesis at UV-induced cyclobutane thymine dimers. J Biol Chem 2011; 287:9222-9. [PMID: 22194617 DOI: 10.1074/jbc.m111.306852] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cyclobutane thymine dimers (T-T) comprise the majority of DNA damage caused by short wavelength ultraviolet radiation. These lesions generally block replicative DNA polymerases and are repaired by nucleotide excision repair or bypassed by translesion polymerases in the nucleus. Mitochondria lack nucleotide excision repair, and therefore, it is important to understand how the sole mitochondrial DNA polymerase, pol γ, interacts with irreparable lesions such as T-T. We performed in vitro DNA polymerization assays to measure the kinetics of incorporation opposite the lesion and bypass of the lesion by pol γ with a dimer-containing template. Exonuclease-deficient pol γ bypassed thymine dimers with low relative efficiency; bypass was attenuated but still detectable when using exonuclease-proficient pol γ. When bypass did occur, pol γ misincorporated a guanine residue opposite the 3'-thymine of the dimer only 4-fold less efficiently than it incorporated an adenine. Surprisingly, the pol γ exonuclease-proficient enzyme excised the incorrectly incorporated guanine at similar rates irrespective of the nature of the thymines in the template. In the presence of all four dNTPs, pol γ extended the primer after incorporation of two adenines opposite the lesion with relatively higher efficiency compared with extension past either an adenine or a guanine incorporated opposite the 3'-thymine of the T-T. Our results suggest that T-T usually stalls mitochondrial DNA replication but also suggest a mechanism for the introduction of point mutations and deletions in the mitochondrial genomes of chronically UV-exposed cells.
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Affiliation(s)
- Rajesh Kasiviswanathan
- Laboratory of Molecular Genetics, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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22
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Ramya D, Siddikuzzaman, Manjamalai A, Berlin Grace V. Chemoprotective effect of all-trans retinoic acid (ATRA) on oxidative stress and lung metastasis induced by benzo(a)pyrene. Immunopharmacol Immunotoxicol 2011; 34:317-25. [DOI: 10.3109/08923973.2011.604087] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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23
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Jeppesen DK, Bohr VA, Stevnsner T. DNA repair deficiency in neurodegeneration. Prog Neurobiol 2011; 94:166-200. [PMID: 21550379 DOI: 10.1016/j.pneurobio.2011.04.013] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/18/2011] [Accepted: 04/22/2011] [Indexed: 01/17/2023]
Abstract
Deficiency in repair of nuclear and mitochondrial DNA damage has been linked to several neurodegenerative disorders. Many recent experimental results indicate that the post-mitotic neurons are particularly prone to accumulation of unrepaired DNA lesions potentially leading to progressive neurodegeneration. Nucleotide excision repair is the cellular pathway responsible for removing helix-distorting DNA damage and deficiency in such repair is found in a number of diseases with neurodegenerative phenotypes, including Xeroderma Pigmentosum and Cockayne syndrome. The main pathway for repairing oxidative base lesions is base excision repair, and such repair is crucial for neurons given their high rates of oxygen metabolism. Mismatch repair corrects base mispairs generated during replication and evidence indicates that oxidative DNA damage can cause this pathway to expand trinucleotide repeats, thereby causing Huntington's disease. Single-strand breaks are common DNA lesions and are associated with the neurodegenerative diseases, ataxia-oculomotor apraxia-1 and spinocerebellar ataxia with axonal neuropathy-1. DNA double-strand breaks are toxic lesions and two main pathways exist for their repair: homologous recombination and non-homologous end-joining. Ataxia telangiectasia and related disorders with defects in these pathways illustrate that such defects can lead to early childhood neurodegeneration. Aging is a risk factor for neurodegeneration and accumulation of oxidative mitochondrial DNA damage may be linked with the age-associated neurodegenerative disorders Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Mutation in the WRN protein leads to the premature aging disease Werner syndrome, a disorder that features neurodegeneration. In this article we review the evidence linking deficiencies in the DNA repair pathways with neurodegeneration.
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Affiliation(s)
- Dennis Kjølhede Jeppesen
- Danish Centre for Molecular Gerontology and Danish Aging Research Center, University of Aarhus, Department of Molecular Biology, Aarhus, Denmark
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24
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Lukashevich OV, Baskunov VB, Darii MV, Kolbanovskiy A, Baykov AA, Gromova ES. Dnmt3a-CD is less susceptible to bulky benzo[a]pyrene diol epoxide-derived DNA lesions than prokaryotic DNA methyltransferases. Biochemistry 2011; 50:875-81. [PMID: 21174446 DOI: 10.1021/bi101717b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Benzo[a]pyrene (B[a]P) is a well-characterized environmental polycyclic aromatic hydrocarbon pollutant. In living organisms, B[a]P is metabolized to the genotoxic anti-benzo[a]pyrene diol epoxide that reacts with cellular DNA to form stereoisomeric anti-B[a]PDE-N(2)-dG adducts. In this study, we explored the effects of adduct stereochemistry and position in double-stranded DNA substrates on the functional characteristics of the catalytic domain of murine de novo DNA methyltransferase Dnmt3a (Dnmt3a-CD). A number of 18-mer duplexes containing site-specifically incorporated (+)- and (-)-trans-anti-B[a]PDE-N(2)-dG lesions located 3'- and 5'-adjacent to and opposite the target cytosine residue were prepared. Dnmt3a-CD binds cooperatively to the DNA duplexes with an up to 5-fold greater affinity compared to that for the undamaged DNA duplexes. Methylation assays showed a 1.7-6.3-fold decrease in the methylation reaction rates for the damaged duplexes. B[a]PDE modifications stimulated a nonproductive binding and markedly favored substrate inhibition of Dnmt3a-CD in a manner independent of DNA methylation status. The latter effect was sensitive to the position and stereochemistry of the B[a]PDE-N(2)-dG adducts. The overall effect of trans-anti-B[a]PDE-N(2)-dG adducts on Dnmt3a-CD was less detrimental than in the case of the prokaryotic methyltransferases we previously investigated.
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25
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DNA repair in organelles: Pathways, organization, regulation, relevance in disease and aging. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:186-200. [DOI: 10.1016/j.bbamcr.2010.10.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 10/01/2010] [Accepted: 10/05/2010] [Indexed: 12/20/2022]
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26
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Rinaldi T, Dallabona C, Ferrero I, Frontali L, Bolotin-Fukuhara M. Mitochondrial diseases and the role of the yeast models. FEMS Yeast Res 2010; 10:1006-22. [PMID: 20946356 DOI: 10.1111/j.1567-1364.2010.00685.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Nowadays, mitochondrial diseases are recognized and studied with much attention and they cannot be considered anymore as 'rare diseases'. Yeast has been an instrumental organism to understand the genetic and molecular aspects of the many roles of mitochondria within the cells. Thanks to the general conservation of mitochondrial genes and pathways between human and yeast, it can also be used to model some diseases. In this review, we focus on the most recent topics, exemplifying those for which yeast models have been especially valuable.
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Affiliation(s)
- Teresa Rinaldi
- Department of Cell and Developmental Biology, Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
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27
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Jung D, Cho Y, Collins LB, Swenberg JA, Di Giulio RT. Effects of benzo[a]pyrene on mitochondrial and nuclear DNA damage in Atlantic killifish (Fundulus heteroclitus) from a creosote-contaminated and reference site. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2009; 95:44-51. [PMID: 19726093 PMCID: PMC2776085 DOI: 10.1016/j.aquatox.2009.08.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 08/05/2009] [Accepted: 08/06/2009] [Indexed: 05/04/2023]
Abstract
Benzo[a]pyrene (BaP) is a known genotoxicant that affects both mitochondrial and nuclear DNA (mtDNA, nDNA). Here, we examined mtDNA and nDNA damage in the Atlantic killifish (Fundulus heteroclitus) from a highly contaminated Superfund site (Elizabeth River, VA, USA) and from a reference site (King's Creek, VA, USA) that were dosed with 10 mg/kg BaP. Using the long amplicon quantitative PCR technique, we observed similar increases in mitochondrial and nuclear DNA damage in King's Creek fish treated with BaP. Killifish from the Elizabeth River showed high levels of basal nDNA and mtDNA damage compared to fish from the reference site, but the level of damage induced due to BaP treatment was much lower in Elizabeth River killifish compared to King's Creek fish. Laboratory-reared offspring from both populations showed increased BaP-induced damage in mtDNA, relative to nDNA. Similar to the adult experiment, the Elizabeth River larvae had higher levels of basal DNA damage than those from the reference site, but were less impacted by BaP exposure. Measurements of oxidative DNA damage (8-oxo-deoxyguanine by LC-MS/MS) showed no differences among treatment groups, suggesting that the majority of DNA damage is from covalent binding of BaP metabolites to DNA. This study shows for the first time that mitochondria can be an important target of BaP toxicity in fish, indicating that BaP exposures could have important energetic consequences. Results also suggest that multi-generational exposures in the wild may lead to adaptations that dampen DNA damage arising from BaP exposure.
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Affiliation(s)
- Dawoon Jung
- Nicholas School of the Environment, Duke University, Durham, NC 27708
| | - Youngeun Cho
- Nicholas School of the Environment, Duke University, Durham, NC 27708
| | - Leonard B. Collins
- Center for Environmental Health and Susceptibility, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599
| | - James A. Swenberg
- Center for Environmental Health and Susceptibility, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599
| | - Richard T. Di Giulio
- Nicholas School of the Environment, Duke University, Durham, NC 27708
- Corresponding Author: Nicholas School of the Environment, Duke University, Box 90328, Durham, NC 27708, Phone: 1-919-613-8024, Fax: 1-919-668-1799,
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28
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Partridge MA, Huang SXL, Kibriya MG, Ahsan H, Davidson MM, Hei TK. Environmental mutagens induced transversions but not transitions in regulatory region of mitochondrial DNA. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:301-4. [PMID: 19184745 DOI: 10.1080/15287390802526381] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
One of the long-term objectives of the research in our laboratory was to determine whether mitochondrial DNA (mtDNA) mutations were generated in cell lines exposed to a variety of known mutagens. Many of these mutagens are known to increase oxidative stress in the cell, and one potential outcome of this would be an increased incidence of point mutations in mtDNA. Recently, there has been some controversy regarding the validity of point mutations in the regulatory region of mtDNA as a predictive or causative marker for carcinogenesis. Studies were undertaken to assess whether nuclear mutagens such as arsenic (As), asbestos, and ultraviolet (UV) and gamma-radiation, induced both heteroplasmic and homoplasmic point mutations in mtDNA. A direct sequencing approach was used to reduce the occurrence of experimental errors and cross-checked all base changes with databases of known polymorphisms. Our results showed that, while base changes did occur, there was no marked difference between the number of changes in treated and untreated cells. Furthermore, in human lymphocyte samples from subjects exposed to As, most of these base changes were previously reported. Interestingly, there was an increase in the number of transversions (purine ( pyrimidine) in smokers from a human population study, but as with the findings in cell culture samples, there was no difference in the total number of base changes. Data suggest that only a change in the number of rare transversions would be indicative of an increase in point mutations in mtDNA after exposure to mutagens.
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Affiliation(s)
- Michael A Partridge
- Center for Radiological Research, Columbia University, New York, NY 10032, USA
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29
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Venkatesan PN, Rajendran P, Ekambaram G, Sakthisekaran D. Combination therapeutic effect of cisplatin along with Solanum trilobatum on benzo(a)pyrene induced experimental lung carcinogenesis. Nat Prod Res 2008; 22:1094-106. [PMID: 18780251 DOI: 10.1080/14786410802267601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Lung cancer is one of the leading causes of cancer death in the world and is notoriously difficult to treat effectively. In the present study, male Swiss albino mice were divided into five groups of six animals each: group I animals received corn oil orally and served as a control; group II cancer-induced animals received benzo(a)pyrene (B[a]P) (50 mg kg(-1) bodyweight dissolved in corn oil, orally) twice weekly for four successive weeks; group III cancer-bearing animals (after 12 weeks of induction) were treated with cisplatin (6 mg kg(-1) bodyweight, i.p.) once weekly for 4 weeks; group IV cancer-bearing animals were treated with cisplatin along with Solanum trilobatum (300 mg kg(-1) bodyweight) orally once weekly for 4 weeks; and group V animals constituted the drug control treated with cisplatin along with S. trilobatum. The serum, lung and liver were investigated biochemically for aryl hydrocarbon hydroxylase, gamma-glutamyl transpeptidase, 5'-nucleotidase, lactate dehydrogenase (LDH) and protein-bound carbohydrate components (hexose, hexosamine and sialic acid). These enzyme activities were increased significantly in cancer-bearing animals compared with control animals. The elevation of these in cancer-bearing animals was indicative of the persistent deteriorating effect of B[a]P in cancer-bearing animals. Our data suggest that cisplatin, administered with S. trilobatum, may extend its chemotherapeutic effect through modulating protein-bound carbohydrate levels and marker enzymes, as they are indicators of cancer. The combination of cisplatin with S. trilobatum could effectively treat the B[a]P-induced lung cancer in mice by offering protection from reactive oxygen species damage and also by suppressing cell proliferation.
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Affiliation(s)
- P N Venkatesan
- Department of Medical Biochemistry, Dr ALM PG Institute of Basic Medical Sciences, University of Madras, Chennai, India.
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30
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Stabenau EK, Sasser A, Schulte C. The effects of pyrene exposure on exercise performance, muscle contraction, and mitochondrial O(2) consumption in the leopard frog (Rana pipiens). JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2008; 43:576-583. [PMID: 18393064 DOI: 10.1080/10934520801893535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The present study exposed frogs to the PAH pyrene and measured exercise performance, muscle contractile ability, mitochondrial O(2) consumption, and membrane potential. Leopard frogs, Rana pipiens, were exposed for seven days in control or pyrene saturated water aquaria. Frogs were randomly placed into one of four groups: (i) pyrene-exposed exercised, (ii) control, exercised, (iii) pyrene-exposed, non-exercised, and (iv) control, non-exercised. Following the acute exposure, exercise duration, muscle contractile ability, blood gases and pH, glycogen levels, crossbridge formation and contractile length, and mitochondrial respiration were measured. The data revealed that pyrene exposure produced many adverse effects in Leopard frogs including significant reductions in exercise performance, muscle contractile ability, and alterations to muscle mitochondrial O(2) consumption and membrane potential. These data suggest that PAH exposure may limit survival for frogs in the wild by limiting foraging, mating, and predator avoidance behaviors.
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Affiliation(s)
- Erich K Stabenau
- Department of Biology, Bradley University, Peoria, Illinois 61625, USA.
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Yagi H, Jerina DM. Fluorinated Alcohol Mediated Displacement of the C10 Acetoxy Group of Benzo[a]pyrene-7,8,9,10-tetrahydrotetraol Tetraacetates: A New Route to Diol Epoxide−Deoxyguanosine Adducts. J Org Chem 2007; 72:9983-90. [DOI: 10.1021/jo701705c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Haruhiko Yagi
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, the National Institutes of Health, DHHS, Bethesda, Maryland 20892
| | - Donald M. Jerina
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, the National Institutes of Health, DHHS, Bethesda, Maryland 20892
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Vineyard D, Zhang X, Donnelly A, Lee I, Berdis AJ. Optimization of non-natural nucleotides for selective incorporation opposite damaged DNA. Org Biomol Chem 2007; 5:3623-30. [PMID: 17971991 DOI: 10.1039/b712480e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The promutagenic process known as translesion DNA synthesis reflects the ability of a DNA polymerase to misinsert a nucleotide opposite a damaged DNA template. To study the underlying mechanism of nucleotide selection during this process, we quantified the incorporation of various non-natural nucleotide analogs opposite an abasic site, a non-templating DNA lesion. Our kinetic studies using the bacteriophage T4 DNA polymerase reveal that the pi-electron surface area of the incoming nucleotide substantially contributes to the efficiency of incorporation opposite an abasic site. A remaining question is whether the selective insertion of these non-hydrogen-bonding analogs can be achieved through optimization of shape and pi-electron density. In this report, we describe the synthesis and kinetic characterization of four novel nucleotide analogs, 5-cyanoindolyl-2'-deoxyriboside 5'-triphosphate (5-CyITP), 5-ethyleneindolyl-2'-deoxyriboside 5'-triphosphate (5-EyITP), 5-methylindolyl-2'-deoxyriboside 5'-triphosphate (5-MeITP), and 5-ethylindolyl-2'-deoxyriboside 5'-triphosphate (5-EtITP). Kinetic analyses indicate that the overall catalytic efficiencies of all four nucleotides are related to their base-stacking properties. In fact, the catalytic efficiency for nucleotide incorporation opposite an abasic site displays a parabolic trend in the overall pi-electron surface area of the non-natural nucleotide. In addition, each non-natural nucleotide is incorporated opposite templating DNA approximately 100-fold worse than opposite an abasic site. These data indicate that selectivity for incorporation opposite damaged DNA can be achieved through optimization of the base-stacking properties of the incoming nucleotide.
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Affiliation(s)
- Diana Vineyard
- Department of Pharmacology, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
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Graziewicz MA, Bienstock RJ, Copeland WC. The DNA polymerase gamma Y955C disease variant associated with PEO and parkinsonism mediates the incorporation and translesion synthesis opposite 7,8-dihydro-8-oxo-2'-deoxyguanosine. Hum Mol Genet 2007; 16:2729-39. [PMID: 17725985 PMCID: PMC2131726 DOI: 10.1093/hmg/ddm227] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial DNA is replicated and repaired by DNA polymerase gamma (pol gamma), encoded by the POLG gene. The Y955C substitution in POLG leads to autosomal dominant progressive external ophthalmoplegia (PEO) with other severe phenotypes. PEO patients with this mutation can further develop parkinsonism or premature ovarian failure. Mouse and yeast models with this mutation show enhanced amounts of oxidative lesions and increased mtDNA damage. In DNA pol gamma, Tyr955 plays a critical role in catalysis and high fidelity DNA synthesis. 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG) is one of the most common oxidative lesions in DNA and can promote transversion mutations. Mitochondria are thought to be a major source of endogenous reactive oxygen species that can react with dG to form 8-oxo-dG as one of the more common products. DNA polymerases can mitigate mutagenesis by 8-oxo-dG through allosteric interactions from amino acid side chains, which limit the anti-conformation of the 8-oxo-dG template base during translesion DNA synthesis. Here, we show that the Y955C pol gamma displays relaxed discrimination when either incorporating 8-oxo-dGTP or translesion synthesis opposite 8-oxo-dG. Molecular modeling and biochemical analysis suggest that this residue, Tyr955, in conjunction with Phe961 helps attenuate the anti-conformation in human pol gamma for error free bypass of 8-oxo-dG and substitution to Cys allows the mutagenic syn conformation. Collectively, these results offer a biochemical link between the observed oxidative stress in model systems and parkinsonism in patients, suggesting that patients harboring the Y955C POLG mutation may undergo enhanced oxidative stress and DNA mutagenesis.
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Affiliation(s)
- Maria A. Graziewicz
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Rachelle J. Bienstock
- Scientific Computing Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - William C. Copeland
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- To whom correspondence should be addressed at: Laboratory of Molecular Genetics National Institute of Environmental Health Sciences, PO Box 12233, Research Triangle Park, NC 27709, USA. Tel: +1 9195414792; Fax: +1 9195417613;
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Yagi H, Jerina DM. Fluorinated alcohol mediated control over cis vs trans opening of benzo[a]pyrene-7,8-diol 9,10-epoxides at C-10 by the exocyclic amino groups of O6-allyl protected deoxyguanosine and of deoxyadenosine. J Org Chem 2007; 72:6037-45. [PMID: 17608435 DOI: 10.1021/jo070303c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A detailed study was carried out on the stereoselective control of cis- vs trans-opening of (+/-)-7beta,8alpha-dihydroxy-9beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene {B[a]P DE-1 (1)} and (+/-)-7beta,8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene {B[a]P DE-2 (2)} at C-10 by the exocyclic amino groups of protected purine nucleosides in the fluorinated alcohols trifluoroethanol (TFE), hexafluoropropan-2-ol (HFP), and perfluoro-tert-butanol (PFTB). Addition of the 2-amino group of O6-allyl-3',5'-di-O-(tert-butyldimethylsilyl)-2'-deoxyguanosine (3) and of the 6-amino group of 3',5'-di-O-(tert-butyldimethylsilyl)-2'-deoxyadenosine (4) occurs at C-10 of the epoxides. The observed cis:trans ratio for the reaction of DE-1 (1) in the presence of 5 equiv of 3 over the range of 10-250 equiv of fluorinated alcohol varied from 53:47 to 87:13 for TFE, 60:40 to 92:8 for HFP, and 52:48 to 73:27 for PFTB. The corresponding ratios for DE-2 (2) varied from 22:78 to 72:28 for HFP under the same set of conditions. In contrast, the corresponding ratios for DE-2 (2) remained unchanged ( approximately 40:60) for TFE and for PFTB over the range of 25-250 molar equiv. Unlike the addition of the dGuo reactant 3, the corresponding addition of the dAdo reactant (4) to the DEs (1 or 2) in over 25 molar equiv of TFE occurred highly stereoselectively to afford only cis adducts for both DEs. A highly efficient HPLC separation of dGuo adduct diastereomers derived from DE-2 (2) was developed using acetone as a modifier in CH2Cl2 or in n-hexane. Through the use of varying molar ratios of the different fluorinated alcohols described above and the newly developed HPLC separation method, the four possible phosphoramidites (cis/trans, R/S) of the B[a]P DE-2 N2-dGuo adducts can be prepared in an efficient fashion on gram scale for use in oligonucleotide synthesis.
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Affiliation(s)
- Haruhiko Yagi
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, The National Institutes of Health/DHHS, Bethesda, MD 20892, USA
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Johnson AA, Sayer JM, Yagi H, Patil SS, Debart F, Maier MA, Corey DR, Vasseur JJ, Burke TR, Marquez VE, Jerina DM, Pommier Y. Effect of DNA modifications on DNA processing by HIV-1 integrase and inhibitor binding: role of DNA backbone flexibility and an open catalytic site. J Biol Chem 2006; 281:32428-38. [PMID: 16943199 DOI: 10.1074/jbc.m605101200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integration of the viral cDNA into host chromosomes is required for viral replication. Human immunodeficiency virus integrase catalyzes two sequential reactions, 3'-processing (3'-P) and strand transfer (ST). The first integrase inhibitors are undergoing clinical trial, but interactions of inhibitors with integrase and DNA are not well understood in the absence of a co-crystal structure. To increase our understanding of integrase interactions with DNA, we examined integrase catalysis with oligonucleotides containing DNA backbone, base, and groove modifications placed at unique positions surrounding the 3'-processing site. 3'-Processing was blocked with substrates containing constrained sugars and alpha-anomeric residues, suggesting that integrase requires flexibility of the phosphodiester backbone at the 3'-P site. Of several benzo[a]pyrene 7,8-diol 9,10-epoxide (BaP DE) adducts tested, only the adduct in the minor groove at the 3'-P site inhibited 3'-P, suggesting the importance of the minor groove contacts for 3'-P. ST occurred in the presence of bulky BaP DE DNA adducts attached to the end of the viral DNA suggesting opening of the active site for ST. Position-specific effects of these BaP DE DNA adducts were found for inhibition of integrase by diketo acids. Together, these results demonstrate the importance of DNA structure and specific contacts with the viral DNA processing site for inhibition by integrase inhibitors.
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Affiliation(s)
- Allison A Johnson
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health/DHHS, Bethesda, MD 20892, USA
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Senthilnathan P, Padmavathi R, Magesh V, Sakthisekaran D. Chemotherapeutic efficacy of paclitaxel in combination with Withania somnifera on benzo(a)pyrene-induced experimental lung cancer. Cancer Sci 2006; 97:658-64. [PMID: 16827807 PMCID: PMC11159414 DOI: 10.1111/j.1349-7006.2006.00224.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Lung cancer is one of the leading causes of cancer death in the world and is notoriously difficult to treat effectively. In the present study, male Swiss albino mice were divided into five groups of six animals each: group I animals received corn oil orally and served as a control; group II cancer-induced animals received benzo(a)pyrene (50 mg/kg bodyweight dissolved in corn oil, orally) twice weekly for four successive weeks; group III cancer-bearing animals (after 12 weeks of induction) were treated with paclitaxel (33 mg/kg bodyweight, i.p.) once weekly for 4 weeks; group IV cancer-bearing animals were treated with paclitaxel along with Withania somnifera (400 mg/kg bodyweight) orally once weekly for 4 weeks; and group V animals constituted the drug control treated with paclitaxel along with W. somnifera. The serum, lung and liver were investigated biochemically for aryl hydrocarbon hydroxylase, gamma-glutamyl transpeptidase, 5'-nucleotidase, lactate dehydrogenase and protein-bound carbohydrate components (hexose, hexosamine and sialic acid). These enzyme activities were increased significantly in cancer-bearing animals compared with control animals. The elevation of these in cancer-bearing animals was indicative of the persistent deteriorating effect of benzo(a)pyrene in cancer-bearing animals. Our data suggest that paclitaxel, administered with W. somnifera, may extend its chemotherapeutic effect through modulating protein-bound carbohydrate levels and marker enzymes, as they are indicators of cancer. The combination of paclitaxel with W. somnifera could effectively treat the benzo(a)pyrene-induced lung cancer in mice by offering protection from reactive oxygen species damage and also by suppressing cell proliferation.
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Affiliation(s)
- Palaniyandi Senthilnathan
- Department of Medical Biochemistry, ALM Postgraduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600-113, India
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37
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Graziewicz MA, Longley MJ, Copeland WC. DNA polymerase gamma in mitochondrial DNA replication and repair. Chem Rev 2006; 106:383-405. [PMID: 16464011 DOI: 10.1021/cr040463d] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maria A Graziewicz
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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Choudhary S, Doherty KM, Handy CJ, Sayer JM, Yagi H, Jerina DM, Brosh RM. Inhibition of Werner syndrome helicase activity by benzo[a]pyrene diol epoxide adducts can be overcome by replication protein A. J Biol Chem 2005; 281:6000-9. [PMID: 16380375 DOI: 10.1074/jbc.m510122200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
RecQ helicases are believed to function in repairing replication forks stalled by DNA damage and may also play a role in the intra-S-phase checkpoint, which delays the replication of damaged DNA, thus permitting repair to occur. Since little is known regarding the effects of DNA damage on RecQ helicases, and because the replication and recombination defects in Werner syndrome cells may reflect abnormal processing of damaged DNA associated with the replication fork, we examined the effects of specific bulky, covalent adducts at N(6) of deoxyadenosine (dA) or N(2) of deoxyguanosine (dG) on Werner (WRN) syndrome helicase activity. The adducts are derived from the optically active 7,8-diol 9,10-epoxide (DE) metabolites of the carcinogen benzo[a]pyrene (BaP). The results demonstrate that WRN helicase activity is inhibited in a strand-specific manner by BaP DE-dG adducts only when on the translocating strand. These adducts either occupy the minor groove without significant perturbation of DNA structure (trans adducts) or cause base displacement at the adduct site (cis adducts). In contrast, helicase activity is only mildly affected by intercalating BaP DE-dA adducts that locally perturb DNA double helical structure. This differs from our previous observation that intercalating dA adducts derived from benzo[c]phenanthrene (BcPh) DEs inhibit WRN activity in a strand- and stereospecific manner. Partial unwinding of the DNA helix at BaP DE-dA adduct sites may make such adducted DNAs more susceptible to the action of helicase than DNA containing the corresponding BcPh DE-dA adducts, which cause little or no destabilization of duplex DNA. The single-stranded DNA binding protein RPA, an auxiliary factor for WRN helicase, enabled the DNA unwinding enzyme to overcome inhibition by either the trans-R or cis-R BaP DE-dG adduct, suggesting that WRN and RPA may function together to unwind duplex DNA harboring specific covalent adducts that otherwise block WRN helicase acting alone.
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Affiliation(s)
- Saba Choudhary
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health/DHHS, Baltimore, MD 21224, USA
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Larsen NB, Rasmussen M, Rasmussen LJ. Nuclear and mitochondrial DNA repair: similar pathways? Mitochondrion 2005; 5:89-108. [PMID: 16050976 DOI: 10.1016/j.mito.2005.02.002] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Revised: 01/31/2005] [Accepted: 02/03/2005] [Indexed: 02/08/2023]
Abstract
Mitochondrial DNA (mtDNA) alterations are implicated in a broad range of human diseases and alterations of the mitochondrial genome are assumed to be a result of its high susceptibility to oxidative damage and its limited DNA repair compared to nuclear DNA (nDNA). Characterization of DNA repair mechanisms has generally focused on these processes in nDNA but increasing interest and research effort have contributed to our knowledge of the mechanisms underlying DNA repair in mitochondria. In this review, we make comparisons between nDNA and mtDNA repair pathways and propose a model for how these pathways interact in mitochondria.
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Affiliation(s)
- Nicolai Balle Larsen
- Department of Life Sciences and Chemistry, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark
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40
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Lewis W, Haase CP, Miller YK, Ferguson B, Stuart T, Ludaway T, McNaught J, Russ R, Steltzer J, Santoianni R, Long R, Fiermonte G, Palmieri F. Transgenic expression of the deoxynucleotide carrier causes mitochondrial damage that is enhanced by NRTIs for AIDS. J Transl Med 2005; 85:972-81. [PMID: 15951836 DOI: 10.1038/labinvest.3700301] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) are antiretrovirals for AIDS with limiting mitochondrial side effects. The mitochondrial deoxynucleotide carrier (DNC) transports phosphorylated nucleosides for mitochondrial DNA replication and can transport phosphorylated NRTIs into mitochondria. Transgenic mice (TG) that exclusively overexpress DNC in the heart tested DNC's role in mitochondrial dysfunction from NRTIs. Two TG lines were created that overexpressed the human DNC gene in murine myocardium. Cardiac and mitochondrial structure and function were examined by magnetic resonance imaging, echocardiography, electrocardiography, transmission electron microscopy, and plasma lactate. Antiretroviral combinations (HAART) that contained NRTIs (stavudine (2', 3'-didehydro-2', 3'-deoxythymidine or d4T)/lamivudine/indinavir; or zidovudine (3' azido-3'-deoxythymidine or AZT)/lamivudine/indinavir; 35 days) were administered to simulate AIDS therapy. In parallel, a HAART combination without NRTIs (nevirapine/efavirenz/indinavir; 35 days) served as an NRTI-sparing, control regimen. Untreated DNC TGs exhibited normal cardiac function but abnormal mitochondrial ultrastructure. HAART that contained NRTIs caused cardiomyopathy in TGs with increased left ventricle mass and volume, heart rate variability, and worse mitochondrial ultrastructural defects. In contrast, treatment with an NRTI-sparing HAART regimen caused no cardiac changes. Data suggest the DNC is integral to mitochondrial homeostasis in vivo and may relate mechanistically to mitochondrial dysfunction in patients treated with HAART regimens that contain NRTIs.
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Affiliation(s)
- William Lewis
- Department of Pathology, Emory University School of Medicine, Atlanta, GA, USA.
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Pittelkow M, Christensen JB, Sølling TI. Substituent effects on the stability of extended benzylic carbocations: a computational study of conjugation. Org Biomol Chem 2005; 3:2441-9. [PMID: 15976861 DOI: 10.1039/b504967a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A set of design rules for the prediction of relative stabilities of methoxy substituted naphthyl methyl carbocations are presented based on a series of DFT calculations. The peri-effect, over-crowding, substitutions on the ring carrying the CH(2)(+) group and substitution on the opposite ring are the principal factors that influence the stability of the carbocations. All of these factors have to be taken simultaneously into account. The most pronounced destabilization occurs when the methyl part of the methoxy substituent lies out of the plane of the aromatic core because this causes the resonance stabilization of the carbocation to become hindered. The performance of the DFT-calculations was assessed on the results of a G3(MP2)//B3LYP calculation-a method that is known to predict energies to within chemical accuracy. These values were found to compare well with those obtained at the B3LYP/6-31G(d) level. Thus, a computationally inexpensive method such as the B3LYP/6-31G(d) might prove to be a powerful tool in the design of future complex extended aromatic systems.
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Affiliation(s)
- Michael Pittelkow
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, Denmark
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42
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Cho BP. Dynamic conformational heterogeneities of carcinogen-DNA adducts and their mutagenic relevance. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2004; 22:57-90. [PMID: 16291518 DOI: 10.1081/lesc-200038217] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Arylamines and polycyclic aromatic hydrocarbons (PAHs), which are known as "bulky" carcinogens, have been studied extensively and upon activation in vivo, react with cellular DNA to form DNA-adducts. The available structure data accumulated thus far has revealed that conformational heterogeneity is a common theme among duplex DNA modified with these carcinogens. Several conformationally diverse structures have been elucidated and found to be in equilibrium in certain cases. The dynamics of the heterogeneity appear to be modulated by the nature of the adduct structure and the base sequences neighboring the lesion site. These can be termed as "adduct- and sequence-induced conformational heterogeneities," respectively. Due to the small energy differences, the population levels of these conformers could readily be altered within the active sites of repair or replicate enzymes. Thus, the complex role of "enzyme-induced conformational heterogeneity" must also be taken into consideration for the establishment of a functional structure-mutation relationship. Ultimately, a major challenge in mutation structural biology is to carry out adduct- and site-specific experiments in a conformationally specific manner within biologically relevant environments. Results from such experiments should provide an accurate account of how a single chemically homogenous adduct gives rise to complex multiple mutations, the earliest step in the induction of cancer.
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Affiliation(s)
- Bongsup P Cho
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02882, USA.
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