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Diamantopoulos MA, Adamopoulos PG, Tsiakanikas P, Nisotakis T, Skourou PC, Scorilas A. Unraveling novel mRNA transcripts of the human DNA N-glycosylase 1 (NTHL1) gene with the implementation of an innovative targeted DNA-seq assay. Gene 2024; 930:148856. [PMID: 39147115 DOI: 10.1016/j.gene.2024.148856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 07/13/2024] [Accepted: 08/12/2024] [Indexed: 08/17/2024]
Abstract
The human NTHL1 gene encodes a DNA glycosylase that plays a key role in the base excision repair (BER) pathway, repairing oxidative DNA damage and maintaining genome integrity. The physiological activity of NTHL1 is crucial in preventing genetic alterations that can lead to cancer. In this study, we employed an innovative targeted DNA sequencing (DNA-seq) methodology to explore the transcriptional landscape of the NTHL1 gene, revealing previously uncharacterized alternative splicing events and novel exons. Our designed approach provided significantly improved sequencing depth and coverage, enabling the identification of novel NTHL1 mRNA transcripts. Bioinformatics analysis confirmed all annotated splice junctions of the main NTHL1 transcripts (v.1 - v.3) and revealed novel mRNA transcripts (NTHL1 v.4 - v.9) derived from splicing events between annotated exons as well as mRNAs containing previously uncharacterized exons (NTHL1 v.10 - v.14). Quantitative PCR analysis highlighted a diverse expression pattern of these novel transcripts across different human cell lines, suggesting cell-specific roles and regulatory mechanisms. Notably, NTHL1 v.5 was overexpressed in luminal A breast cancer cells (MCF-7), while v.13 was prominent in triple negative (BT-20), HER2 + breast cancer (SK-BR-3), prostate, colorectal cancer cells and HEK-293 cells. Our findings suggest that specific novel NTHL1 transcripts may encode protein isoforms with distinct structural features, as indicated by ribosome profiling datasets, while others containing premature termination codons could function as long non-coding RNAs. These insights enhance our understanding of NTHL1 regulatory role and its potential as a biomarker and therapeutic target in human malignancies. This study underscores the importance of exploring the transcriptional diversity of NTHL1 to fully elucidate its role in cancer pathobiology.
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Affiliation(s)
- Marios A Diamantopoulos
- Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis G Adamopoulos
- Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Panagiotis Tsiakanikas
- Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Theodoros Nisotakis
- Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Paraskevi C Skourou
- Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Andreas Scorilas
- Department of Biochemistry and Molecular Biology, National and Kapodistrian University of Athens, Athens, Greece.
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Neurauter CG, Pannone M, Sousa MMLD, Wang W, Kuśnierczyk A, Luna L, Sætrom P, Scheffler K, Bjørås M. Enhanced glutathione levels confer resistance to apoptotic and ferroptotic programmed cell death in NEIL DNA glycosylase deficient HAP1 cells. Free Radic Biol Med 2024; 213:470-487. [PMID: 38301978 DOI: 10.1016/j.freeradbiomed.2024.01.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/12/2024] [Accepted: 01/21/2024] [Indexed: 02/03/2024]
Abstract
The NTHL1 and NEIL1-3 DNA glycosylases are major enzymes in the removal of oxidative DNA base lesions, via the base excision repair (BER) pathway. It is expected that lack of these DNA glycosylases activities would render cells vulnerable to oxidative stress, promoting cell death. Intriguingly, we found that single, double, triple, and quadruple DNA glycosylase knockout HAP1 cells are, however, more resistant to oxidative stress caused by genotoxic agents than wild type cells. Furthermore, glutathione depletion in NEIL deficient cells further enhances resistance to cell death induced via apoptosis and ferroptosis. Finally, we observed higher basal level of glutathione and differential expression of NRF2-regulated genes associated with glutathione homeostasis in the NEIL triple KO cells. We propose that lack of NEIL DNA glycosylases causes aberrant transcription and subsequent errors in protein synthesis. This leads to increased endoplasmic reticulum stress and proteotoxic stress. To counteract the elevated intracellular stress, an adaptive response mediated by increased glutathione basal levels, rises in these cells. This study reveals an unforeseen role of NEIL glycosylases in regulation of resistance to oxidative stress, suggesting that modulation of NEIL glycosylase activities is a potential approach to improve the efficacy of e.g. anti-inflammatory therapies.
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Affiliation(s)
- Christine Gran Neurauter
- Department of Microbiology, Oslo University Hospital and University of Oslo, Oslo, 0424, Norway; Centre for Embryology and Healthy Development, University of Oslo, Oslo, 0373, Norway.
| | - Marco Pannone
- Department of Microbiology, Oslo University Hospital and University of Oslo, Oslo, 0424, Norway; Centre for Embryology and Healthy Development, University of Oslo, Oslo, 0373, Norway; Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
| | - Mirta Mittelstedt Leal de Sousa
- Department of Microbiology, Oslo University Hospital and University of Oslo, Oslo, 0424, Norway; Centre for Embryology and Healthy Development, University of Oslo, Oslo, 0373, Norway; Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
| | - Wei Wang
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
| | - Anna Kuśnierczyk
- Proteomics and Modomics Experimental Core Facility (PROMEC), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
| | - Luisa Luna
- Department of Microbiology, Oslo University Hospital and University of Oslo, Oslo, 0424, Norway; Centre for Embryology and Healthy Development, University of Oslo, Oslo, 0373, Norway.
| | - Pål Sætrom
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
| | - Katja Scheffler
- Department of Neurology, St.Olavs University Hospital, Trondheim, 7006, Norway; Department of Neuromedicine and Movement Science (INB), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
| | - Magnar Bjørås
- Department of Microbiology, Oslo University Hospital and University of Oslo, Oslo, 0424, Norway; Centre for Embryology and Healthy Development, University of Oslo, Oslo, 0373, Norway; Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway.
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Kar A, Degtyareva NP, Doetsch PW. Human NTHL1 expression and subcellular distribution determines cisplatin sensitivity in human lung epithelial and non-small cell lung cancer cells. NAR Cancer 2024; 6:zcae006. [PMID: 38384388 PMCID: PMC10880605 DOI: 10.1093/narcan/zcae006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/11/2024] [Accepted: 02/09/2024] [Indexed: 02/23/2024] Open
Abstract
Base excision repair is critical for maintaining genomic stability and for preventing malignant transformation. NTHL1 is a bifunctional DNA glycosylase/AP lyase that initiates repair of oxidatively damaged pyrimidines. Our recent work established that transient over-expression of NTHL1 leads to acquisition of several hallmarks of cancer in non-tumorigenic immortalized cells likely through interaction with nucleotide excision repair protein XPG. Here, we investigate how NTHL1 expression levels impact cellular sensitivity to cisplatin in non-tumorigenic immortalized cells and five non-small cell lung carcinomas cell lines. The cell line with lowest expression of NTHL1 (H522) shows the highest resistance to cisplatin indicating that decrease in NTHL1 levels may modulate resistance to crosslinking agents in NSCLC tumors. In a complementation study, overexpression of NTHL1 in H522 cell line sensitized it to cisplatin. Using NTHL1 N-terminal deletion mutants defective in nuclear localization we show that cisplatin treatment can alter NTHL1 subcellular localization possibly leading to altered protein-protein interactions and affecting cisplatin sensitivity. Experiments presented in this study reveal a previously unknown link between NTHL1 expression levels and cisplatin sensitivity of NSCLC tumor cells. These findings provide an opportunity to understand how altered NTHL1 expression levels and subcellular distribution can impact cisplatin sensitivity in NSCLC tumor cells.
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Affiliation(s)
- Anirban Kar
- Mutagenesis & DNA Repair Regulation Group, National Institute of Environmental Health Sciences, 111 TW Alexander Dr, Durham, NC 27709, USA
| | - Natalya P Degtyareva
- Mutagenesis & DNA Repair Regulation Group, National Institute of Environmental Health Sciences, 111 TW Alexander Dr, Durham, NC 27709, USA
| | - Paul W Doetsch
- Mutagenesis & DNA Repair Regulation Group, National Institute of Environmental Health Sciences, 111 TW Alexander Dr, Durham, NC 27709, USA
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Jiang Z, Lu J, Tong Y, Yang H, Feng S. Enhancement of acid tolerance of Escherichia coli by introduction of molecule chaperone CbpA from extremophile. World J Microbiol Biotechnol 2023; 39:158. [PMID: 37046107 DOI: 10.1007/s11274-023-03613-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/08/2023] [Indexed: 04/14/2023]
Abstract
Molecular chaperone CbpA from extreme acidophile Acidithiobacillus caldus was applied to improve acid tolerance of Escherichia coli via CRISPR/Cas9. Cell growth and viability of plasmid complementary strain indicated the importance of cbpAAc for bacteria acid tolerance. With in situ gene replacement by CRISPR/Cas9 system, colony formation unit (CFU) of genome recombinant strain BL21-ΔcbpA/AccbpA showed 7.7 times higher cell viability than deficient strain BL21-ΔcbpA and 2.3 times higher than wild type. Cell morphology observation using Field Emission Scanning Electron Microscopy (FESEM) revealed cell breakage of BL21-ΔcbpA and significant recovery of BL21-ΔcbpA/AccbpA. The intracellular ATP level of all strains gradually decreased along with the increased stress time. Particularly, the value of recombinant strain was 56.0% lower than that of deficient strain after 5 h, indicating that the recombinant strain consumed a lot of energy to resist acid stress. The arginine concentration in BL21-ΔcbpA/AccbpA was double that of BL21-ΔcbpA, while the aspartate and glutamate contents were 14.8% and 6.2% higher, respectively, compared to that of wild type. Moreover, RNA-Seq analysis examined 93 genes down-regulated in BL21-ΔcbpA compared to wild type strain, while 123 genes were up-regulated in BL21-ΔcbpA/AccbpA compared to BL21-ΔcbpA, with an emphasis on energy metabolism, transport, and cell components. Finally, the working model in response to acid stress of cbpA from A. caldus was developed. This study constructed a recombinant strain resistant to acid stress and also provided a reference for enhancing microorganisms' robustness to various conditions.
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Affiliation(s)
- Zhenming Jiang
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Jie Lu
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Yanjun Tong
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
- School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, China
| | - Hailin Yang
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China
| | - Shoushuai Feng
- Key Laboratory of Industrial Biotechnology, School of Biotechnology, Ministry of Education, Jiangnan University, Wuxi, China.
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Abstract
Efficient DNA repair is essential to maintain genomic integrity. An average of 30,000 base lesions per cell are removed daily by the DNA glycosylases of the base excision repair machinery. With the advent of whole genome sequencing, many germline mutations in these DNA glycosylases have been identified and associated with various diseases, including cancer. In this graphical review, we discuss the function of the NTHL1 DNA glycosylase and how genomic mutations and altered function of this protein contributes to cancer and aging. We highlight its role in a rare tumor syndrome, NTHL1-associated polyposis (NAP), and summarize various other polymorphisms in NTHL1 that can induce early hallmarks of cancer, including genomic instability and cellular transformation.
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Affiliation(s)
- Lipsa Das
- Department of Cellular and Molecular Medicine and University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ, 85724, United States
| | - Victoria G Quintana
- Department of Cellular and Molecular Medicine and University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ, 85724, United States
| | - Joann B Sweasy
- Department of Cellular and Molecular Medicine and University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ, 85724, United States.
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Bordin DL, Lirussi L, Nilsen H. Cellular response to endogenous DNA damage: DNA base modifications in gene expression regulation. DNA Repair (Amst) 2021; 99:103051. [PMID: 33540225 DOI: 10.1016/j.dnarep.2021.103051] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/19/2022]
Abstract
The integrity of the genetic information is continuously challenged by numerous genotoxic insults, most frequently in the form of oxidation, alkylation or deamination of the bases that result in DNA damage. These damages compromise the fidelity of the replication, and interfere with the progression and function of the transcription machineries. The DNA damage response (DDR) comprises a series of strategies to deal with DNA damage, including transient transcriptional inhibition, activation of DNA repair pathways and chromatin remodeling. Coordinated control of transcription and DNA repair is required to safeguardi cellular functions and identities. Here, we address the cellular responses to endogenous DNA damage, with a particular focus on the role of DNA glycosylases and the Base Excision Repair (BER) pathway, in conjunction with the DDR factors, in responding to DNA damage during the transcription process. We will also discuss functions of newly identified epigenetic and regulatory marks, such as 5-hydroxymethylcytosine and its oxidative products and 8-oxoguanine, that were previously considered only as DNA damages. In light of these resultsthe classical perception of DNA damage as detrimental for cellular processes are changing. and a picture emerges whereDNA glycosylases act as dynamic regulators of transcription, placing them at the intersection of DNA repair and gene expression modulation.
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Affiliation(s)
- Diana L Bordin
- Department of Clinical Molecular Biology, University of Oslo, 0318, Oslo, Norway; Department of Clinical Molecular Biology (EpiGen), Akershus University Hospital, 1478, Lørenskog, Norway
| | - Lisa Lirussi
- Department of Clinical Molecular Biology, University of Oslo, 0318, Oslo, Norway; Department of Clinical Molecular Biology (EpiGen), Akershus University Hospital, 1478, Lørenskog, Norway
| | - Hilde Nilsen
- Department of Clinical Molecular Biology, University of Oslo, 0318, Oslo, Norway; Department of Clinical Molecular Biology (EpiGen), Akershus University Hospital, 1478, Lørenskog, Norway.
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Muruzabal D, Collins A, Azqueta A. The enzyme-modified comet assay: Past, present and future. Food Chem Toxicol 2020; 147:111865. [PMID: 33217526 DOI: 10.1016/j.fct.2020.111865] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 11/08/2020] [Accepted: 11/13/2020] [Indexed: 12/17/2022]
Abstract
The enzyme-modified comet assay was developed in order to detect DNA lesions other than those detected by the standard version (single and double strand breaks and alkali-labile sites). Various lesion-specific enzymes, from the DNA repair machinery of bacteria and humans, have been combined with the comet assay, allowing detection of different oxidized and alkylated bases as well as cyclobutane pyrimidine dimers, mis-incorporated uracil and apurinic/apyrimidinic sites. The enzyme-modified comet assay has been applied in different fields - human biomonitoring, environmental toxicology, and genotoxicity testing (both in vitro and in vivo) - as well as in basic research. Up to now, twelve enzymes have been employed; here we describe the enzymes and give examples of studies in which they have been applied. The bacterial formamidopyrimidine DNA glycosylase (Fpg) and endonuclease III (EndoIII) have been extensively used while others have been used only rarely. Adding further enzymes to the comet assay toolbox could potentially increase the variety of DNA lesions that can be detected. The enzyme-modified comet assay can play a crucial role in the elucidation of the mechanism of action of both direct and indirect genotoxins, thus increasing the value of the assay in the regulatory context.
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Affiliation(s)
- Damián Muruzabal
- Universidad de Navarra, Department of Pharmacology and Toxicology, Faculty of Pharmacy and Nutrition, Irunlarrea 1, 310008, Pamplona, Spain
| | - Andrew Collins
- Department of Nutrition, Institute for Basic Medical Sciences, University of Oslo, Sognsvannsveien 9, 0372, Oslo, Norway
| | - Amaya Azqueta
- Universidad de Navarra, Department of Pharmacology and Toxicology, Faculty of Pharmacy and Nutrition, Irunlarrea 1, 310008, Pamplona, Spain; IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.
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8
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Kodavati M, Wang H, Hegde ML. Altered Mitochondrial Dynamics in Motor Neuron Disease: An Emerging Perspective. Cells 2020; 9:cells9041065. [PMID: 32344665 PMCID: PMC7226538 DOI: 10.3390/cells9041065] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondria plays privotal role in diverse pathways that regulate cellular function and survival, and have emerged as a prime focus in aging and age-associated motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Accumulating evidence suggests that many amyloidogenic proteins, including MND-associated RNA/DNA-binding proteins fused in sarcoma (FUS) and TAR DNA binding protein (TDP)-43, are strongly linked to mitochondrial dysfunction. Animal model and patient studies have highlighted changes in mitochondrial structure, plasticity, replication/copy number, mitochondrial DNA instability, and altered membrane potential in several subsets of MNDs, and these observations are consistent with the evidence of increased excitotoxicity, induction of reactive oxygen species, and activation of intrinsic apoptotic pathways. Studies in MND rodent models also indicate that mitochondrial abnormalities begin prior to the clinical and pathological onset of the disease, suggesting a causal role of mitochondrial dysfunction. Our recent studies, which demonstrated the involvement of specific defects in DNA break-ligation mediated by DNA ligase 3 (LIG3) in FUS-associated ALS, raised a key question of its potential implication in mitochondrial DNA transactions because LIG3 is essential for both mitochondrial DNA replication and repair. This question, as well as how wild-type and mutant MND-associated factors affect mitochondria, remain to be elucidated. These new investigation avenues into the mechanistic role of mitochondrial dysfunction in MNDs are critical to identify therapeutic targets to alleviate mitochondrial toxicity and its consequences. In this article, we critically review recent advances in our understanding of mitochondrial dysfunction in diverse subgroups of MNDs and discuss challenges and future directions.
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Affiliation(s)
- Manohar Kodavati
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX 77030, USA; (M.K.); (H.W.)
| | - Haibo Wang
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX 77030, USA; (M.K.); (H.W.)
| | - Muralidhar L. Hegde
- Department of Neurosurgery, Center for Neuroregeneration, Houston Methodist Research Institute, Houston, TX 77030, USA; (M.K.); (H.W.)
- Department of Neurosurgery, Weill Medical College, New York, NY 10065, USA
- Correspondence:
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9
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Boldinova EO, Khairullin RF, Makarova AV, Zharkov DO. Isoforms of Base Excision Repair Enzymes Produced by Alternative Splicing. Int J Mol Sci 2019; 20:ijms20133279. [PMID: 31277343 PMCID: PMC6651865 DOI: 10.3390/ijms20133279] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 06/29/2019] [Accepted: 07/02/2019] [Indexed: 02/07/2023] Open
Abstract
Transcripts of many enzymes involved in base excision repair (BER) undergo extensive alternative splicing, but functions of the corresponding alternative splice variants remain largely unexplored. In this review, we cover the studies describing the common alternatively spliced isoforms and disease-associated variants of DNA glycosylases, AP-endonuclease 1, and DNA polymerase beta. We also discuss the roles of alternative splicing in the regulation of their expression, catalytic activities, and intracellular transport.
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Affiliation(s)
| | - Rafil F Khairullin
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 9 Parizhskoy Kommuny Str., 420012 Kazan, Russia
| | - Alena V Makarova
- RAS Institute of Molecular Genetics, 2 Kurchatova Sq., 123182 Moscow, Russia.
| | - Dmitry O Zharkov
- Novosibirsk State University, 1 Pirogova St., 630090 Novosibirsk, Russia.
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia.
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10
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Shinmura K, Kato H, Kawanishi Y, Goto M, Tao H, Yoshimura K, Nakamura S, Misawa K, Sugimura H. Defective repair capacity of variant proteins of the DNA glycosylase NTHL1 for 5-hydroxyuracil, an oxidation product of cytosine. Free Radic Biol Med 2019; 131:264-273. [PMID: 30552997 DOI: 10.1016/j.freeradbiomed.2018.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 12/09/2018] [Accepted: 12/11/2018] [Indexed: 12/20/2022]
Abstract
The NTHL1 gene encodes DNA glycosylase, which is involved in base excision repair, and biallelic mutations of this gene result in NTHL1-associated polyposis (NAP), a hereditary disease characterized by colorectal polyposis and multiple types of carcinomas. However, no proper functional characterization of variant NTHL1 proteins has been done so far. Herein, we report functional evaluation of variant NTHL1 proteins to aid in the accurate diagnosis of NAP. First, we investigated whether it would be appropriate to use 5-hydroxyuracil (5OHU), an oxidation product of cytosine, for the evaluation. In the supF forward mutation assay, 5OHU caused an increase of the mutation frequency in human cells, and the C→T mutation was predominant among the 5OHU-induced mutations. In addition, in DNA cleavage activity assay, 5OHU was excised by NTHL1 as well as four other DNA glycosylases (SMUG1, NEIL1, TDG, and UNG2). When human cells overexpressing the five DNA glycosylases were established, it was found that each of the five DNA glycosylases, including NTHL1, had the ability to suppress 5OHU-induced mutations. Based on the above results, we performed functional evaluation of eight NTHL1 variants using 5OHU-containing DNA substrate or shuttle plasmid. The DNA cleavage activity assay showed that the variants of NTHL1, Q90X, Y130X, R153X, and Q287X, but not R19Q, V179I, V217F, or G286S, showed defective repair activity for 5OHU and two other oxidatively damaged bases. Moreover, the supF forward mutation assay showed that the four truncated-type NTHL1 variants showed a reduced ability to suppress 5OHU-induced mutations in human cells. These results suggest that the NTHL1 variants Q90X, Y130X, R153X, and Q287X, but not R19Q, V179I, V217F, or G286S, were defective in 5OHU repair and the alleles encoding them were considered to be pathogenic for NAP.
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Affiliation(s)
- Kazuya Shinmura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi Ward, Hamamatsu, Japan.
| | - Hisami Kato
- Department of Tumor Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi Ward, Hamamatsu, Japan
| | - Yuichi Kawanishi
- Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masanori Goto
- Division of Tumor Pathology, Department of Pathology, Asahikawa Medical University, Asahikawa, Japan
| | - Hong Tao
- Department of Tumor Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi Ward, Hamamatsu, Japan
| | - Katsuhiro Yoshimura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi Ward, Hamamatsu, Japan
| | - Satoki Nakamura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi Ward, Hamamatsu, Japan
| | - Kiyoshi Misawa
- Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Haruhiko Sugimura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi Ward, Hamamatsu, Japan
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11
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Mitochondrial DNA Integrity: Role in Health and Disease. Cells 2019; 8:cells8020100. [PMID: 30700008 PMCID: PMC6406942 DOI: 10.3390/cells8020100] [Citation(s) in RCA: 131] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/25/2019] [Accepted: 01/28/2019] [Indexed: 01/06/2023] Open
Abstract
As the primary cellular location for respiration and energy production, mitochondria serve in a critical capacity to the cell. Yet, by virtue of this very function of respiration, mitochondria are subject to constant oxidative stress that can damage one of the unique features of this organelle, its distinct genome. Damage to mitochondrial DNA (mtDNA) and loss of mitochondrial genome integrity is increasingly understood to play a role in the development of both severe early-onset maladies and chronic age-related diseases. In this article, we review the processes by which mtDNA integrity is maintained, with an emphasis on the repair of oxidative DNA lesions, and the cellular consequences of diminished mitochondrial genome stability.
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12
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Bj Rås KØ, Sousa MML, Sharma A, Fonseca DM, S Gaard CK, Bj Rås M, Otterlei M. Monitoring of the spatial and temporal dynamics of BER/SSBR pathway proteins, including MYH, UNG2, MPG, NTH1 and NEIL1-3, during DNA replication. Nucleic Acids Res 2017; 45:8291-8301. [PMID: 28575236 PMCID: PMC5737410 DOI: 10.1093/nar/gkx476] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 05/15/2017] [Indexed: 12/03/2022] Open
Abstract
Base lesions in DNA can stall the replication machinery or induce mutations if bypassed. Consequently, lesions must be repaired before replication or in a post-replicative process to maintain genomic stability. Base excision repair (BER) is the main pathway for repair of base lesions and is known to be associated with DNA replication, but how BER is organized during replication is unclear. Here we coupled the iPOND (isolation of proteins on nascent DNA) technique with targeted mass-spectrometry analysis, which enabled us to detect all proteins required for BER on nascent DNA and to monitor their spatiotemporal orchestration at replication forks. We demonstrate that XRCC1 and other BER/single-strand break repair (SSBR) proteins are enriched in replisomes in unstressed cells, supporting a cellular capacity of post-replicative BER/SSBR. Importantly, we identify for the first time the DNA glycosylases MYH, UNG2, MPG, NTH1, NEIL1, 2 and 3 on nascent DNA. Our findings suggest that a broad spectrum of DNA base lesions are recognized and repaired by BER in a post-replicative process.
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Affiliation(s)
- Karine Ø Bj Rås
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Mirta M L Sousa
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.,The Central Norway Regional Health Authority, N-7501 Stj⊘rdal, Norway
| | - Animesh Sharma
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.,The Central Norway Regional Health Authority, N-7501 Stj⊘rdal, Norway.,Proteomics and Metabolomics Core Facility (PROMEC), Department of Cancer Research and Molecular Medicine, NTNU, N-7491 Trondheim, Norway
| | - Davi M Fonseca
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.,The Central Norway Regional Health Authority, N-7501 Stj⊘rdal, Norway.,Proteomics and Metabolomics Core Facility (PROMEC), Department of Cancer Research and Molecular Medicine, NTNU, N-7491 Trondheim, Norway
| | - Caroline K S Gaard
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
| | - Magnar Bj Rås
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway.,Department of Microbiology, Oslo University Hospital and University of Oslo, N-0027 Oslo, Norway
| | - Marit Otterlei
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), N-7491 Trondheim, Norway
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13
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Limpose KL, Corbett AH, Doetsch PW. BERing the burden of damage: Pathway crosstalk and posttranslational modification of base excision repair proteins regulate DNA damage management. DNA Repair (Amst) 2017. [PMID: 28629773 DOI: 10.1016/j.dnarep.2017.06.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
DNA base damage and non-coding apurinic/apyrimidinic (AP) sites are ubiquitous types of damage that must be efficiently repaired to prevent mutations. These damages can occur in both the nuclear and mitochondrial genomes. Base excision repair (BER) is the frontline pathway for identifying and excising damaged DNA bases in both of these cellular compartments. Recent advances demonstrate that BER does not operate as an isolated pathway but rather dynamically interacts with components of other DNA repair pathways to modulate and coordinate BER functions. We define the coordination and interaction between DNA repair pathways as pathway crosstalk. Numerous BER proteins are modified and regulated by post-translational modifications (PTMs), and PTMs could influence pathway crosstalk. Here, we present recent advances on BER/DNA repair pathway crosstalk describing specific examples and also highlight regulation of BER components through PTMs. We have organized and reported functional interactions and documented PTMs for BER proteins into a consolidated summary table. We further propose the concept of DNA repair hubs that coordinate DNA repair pathway crosstalk to identify central protein targets that could play a role in designing future drug targets.
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Affiliation(s)
- Kristin L Limpose
- Graduate Program in Cancer Biology, Emory University, Atlanta, GA, 30322, United States
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA, 30322, United States; Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States.
| | - Paul W Doetsch
- Graduate Program in Cancer Biology, Emory University, Atlanta, GA, 30322, United States; Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA, 30322, United States; Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States; Department of Biochemistry, Emory University, Atlanta, GA, 30322, United States.
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14
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Bauer NC, Corbett AH, Doetsch PW. The current state of eukaryotic DNA base damage and repair. Nucleic Acids Res 2015; 43:10083-101. [PMID: 26519467 PMCID: PMC4666366 DOI: 10.1093/nar/gkv1136] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 10/16/2015] [Indexed: 12/15/2022] Open
Abstract
DNA damage is a natural hazard of life. The most common DNA lesions are base, sugar, and single-strand break damage resulting from oxidation, alkylation, deamination, and spontaneous hydrolysis. If left unrepaired, such lesions can become fixed in the genome as permanent mutations. Thus, evolution has led to the creation of several highly conserved, partially redundant pathways to repair or mitigate the effects of DNA base damage. The biochemical mechanisms of these pathways have been well characterized and the impact of this work was recently highlighted by the selection of Tomas Lindahl, Aziz Sancar and Paul Modrich as the recipients of the 2015 Nobel Prize in Chemistry for their seminal work in defining DNA repair pathways. However, how these repair pathways are regulated and interconnected is still being elucidated. This review focuses on the classical base excision repair and strand incision pathways in eukaryotes, considering both Saccharomyces cerevisiae and humans, and extends to some important questions and challenges facing the field of DNA base damage repair.
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Affiliation(s)
- Nicholas C Bauer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Paul W Doetsch
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
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15
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Sampath H. Oxidative DNA damage in disease--insights gained from base excision repair glycosylase-deficient mouse models. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2014; 55:689-703. [PMID: 25044514 DOI: 10.1002/em.21886] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/24/2014] [Indexed: 05/10/2023]
Abstract
Cellular components, including nucleic acids, are subject to oxidative damage. If left unrepaired, this damage can lead to multiple adverse cellular outcomes, including increased mutagenesis and cell death. The major pathway for repair of oxidative base lesions is the base excision repair pathway, catalyzed by DNA glycosylases with overlapping but distinct substrate specificities. To understand the role of these glycosylases in the initiation and progression of disease, several transgenic mouse models have been generated to carry a targeted deletion or overexpression of one or more glycosylases. This review summarizes some of the major findings from transgenic animal models of altered DNA glycosylase expression, especially as they relate to pathologies ranging from metabolic disease and cancer to inflammation and neuronal health.
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Affiliation(s)
- Harini Sampath
- Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, Oregon
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16
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Accumulation of abasic sites induces genomic instability in normal human gastric epithelial cells during Helicobacter pylori infection. Oncogenesis 2014; 3:e128. [PMID: 25417725 PMCID: PMC4259965 DOI: 10.1038/oncsis.2014.42] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 10/07/2014] [Accepted: 10/15/2014] [Indexed: 12/11/2022] Open
Abstract
Helicobacter pylori infection of the human stomach is associated with inflammation that leads to the release of reactive oxygen and nitrogen species (RONs), eliciting DNA damage in host cells. Unrepaired DNA damage leads to genomic instability that is associated with cancer. Base excision repair (BER) is critical to maintain genomic stability during RONs-induced DNA damage, but little is known about its role in processing DNA damage associated with H. pylori infection of normal gastric epithelial cells. Here, we show that upon H. pylori infection, abasic (AP) sites accumulate and lead to increased levels of double-stranded DNA breaks (DSBs). In contrast, downregulation of the OGG1 DNA glycosylase decreases the levels of both AP sites and DSBs during H. pylori infection. Processing of AP sites during different phases of the cell cycle leads to an elevation in the levels of DSBs. Therefore, the induction of oxidative DNA damage by H. pylori and subsequent processing by BER in normal gastric epithelial cells has the potential to lead to genomic instability that may have a role in the development of gastric cancer. Our results are consistent with the interpretation that precise coordination of BER processing of DNA damage is critical for the maintenance of genomic stability.
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17
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Christov PP, Son KJ, Rizzo CJ. Synthesis and characterization of oligonucleotides containing a nitrogen mustard formamidopyrimidine monoadduct of deoxyguanosine. Chem Res Toxicol 2014; 27:1610-8. [PMID: 25136769 PMCID: PMC4164228 DOI: 10.1021/tx5002354] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
![]()
N5-Substituted formamidopyrimidine
adducts have been observed from the reaction of dGuo or DNA with aziridine
containing electrophiles, including nitrogen mustards. However, the
role of substituted Fapy-dGuo adducts in the biological response to
nitrogen mustards and related species has not been extensively explored.
We have developed chemistry for the site-specific synthesis of oligonucleotides
containing an N5-nitrogen mustard Fapy-dGuo
using the phosphoramidite approach. The lesion was found to be a good
substrate for Escherichia coli endonuclease
IV and formamidopyrimidine glycosylase.
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Affiliation(s)
- Plamen P Christov
- Departments of Chemistry and Biochemistry, Center in Molecular Toxicology, and Vanderbilt-Ingram Cancer Center, Vanderbilt University , Nashville, Tennessee 37235, United States
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18
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Muftuoglu M, Mori MP, de Souza-Pinto NC. Formation and repair of oxidative damage in the mitochondrial DNA. Mitochondrion 2014; 17:164-81. [PMID: 24704805 DOI: 10.1016/j.mito.2014.03.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 03/18/2014] [Accepted: 03/18/2014] [Indexed: 12/13/2022]
Abstract
The mitochondrial DNA (mtDNA) encodes for only 13 polypeptides, components of 4 of the 5 oxidative phosphorylation complexes. But despite this apparently small numeric contribution, all 13 subunits are essential for the proper functioning of the oxidative phosphorylation circuit. Thus, accumulation of lesions, mutations and deletions/insertions in the mtDNA could have severe functional consequences, including mitochondrial diseases, aging and age-related diseases. The DNA is a chemically unstable molecule, which can be easily oxidized, alkylated, deaminated and suffer other types of chemical modifications, throughout evolution the organisms that survived were those who developed efficient DNA repair processes. In the last two decades, it has become clear that mitochondria have DNA repair pathways, which operate, at least for some types of lesions, as efficiently as the nuclear DNA repair pathways. The mtDNA is localized in a particularly oxidizing environment, making it prone to accumulate oxidatively generated DNA modifications (ODMs). In this article, we: i) review the major types of ODMs formed in mtDNA and the known repair pathways that remove them; ii) discuss the possible involvement of other repair pathways, just recently characterized in mitochondria, in the repair of these modifications; and iii) address the role of DNA repair in mitochondrial function and a possible cross-talk with other pathways that may potentially participate in mitochondrial genomic stability, such as mitochondrial dynamics and nuclear-mitochondrial signaling. Oxidative stress and ODMs have been increasingly implicated in disease and aging, and thus we discuss how variations in DNA repair efficiency may contribute to the etiology of such conditions or even modulate their clinical outcomes.
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Affiliation(s)
- Meltem Muftuoglu
- Department of Molecular Biology and Genetics, Acibadem University, Atasehir, 34752 Istanbul, Turkey
| | - Mateus P Mori
- Depto. de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, 05508-000 Brazil
| | - Nadja C de Souza-Pinto
- Depto. de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, 05508-000 Brazil.
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19
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Corral R, Lewinger JP, Joshi AD, Levine AJ, Vandenberg DJ, Haile RW, Stern MC. Genetic variation in the base excision repair pathway, environmental risk factors, and colorectal adenoma risk. PLoS One 2013; 8:e71211. [PMID: 23951112 PMCID: PMC3741365 DOI: 10.1371/journal.pone.0071211] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/27/2013] [Indexed: 12/12/2022] Open
Abstract
Cigarette smoking, high alcohol intake, and low dietary folate levels are risk factors for colorectal adenomas. Oxidative damage caused by these three factors can be repaired through the base excision repair pathway (BER). We hypothesized that genetic variation in BER might modify colorectal adenoma risk. In a sigmoidoscopy-based study, we examined associations between 182 haplotype tagging SNPs in 14 BER genes, and colorectal adenoma risk, and examined their potential role as modifiers of the effect cigarette smoking, alcohol intake, and dietary folate levels. Among all individuals, no statistically significant associations between BER SNPs and adenoma risk persisted after correction for multiple comparisons. However, among Asian-Pacific Islanders we observed two SNPs in FEN1 and one in NTHL1, and among African-Americans one SNP in APEX1 that were associated with colorectal adenoma risk. Significant associations were also observed between SNPs in the NEIL2 gene and rectal adenoma risk. Three SNPS modified the effect of smoking (MUTYH interaction p = 0.002; OGG1 interaction p = 0.013); FEN1 interaction p = 0.013)), one SNP in LIG3 modified the effect of alcohol consumption (interaction p = 0.024) and two SNPs in LIG3 modified the effect of dietary folate (interaction p = 0.001 and p = 0.08) on colorectal adenoma risk. These findings support a role for genetic variants in the BER pathway as potential modifiers of colorectal adenoma risk. Our findings strengthen the role of oxidative damage induced by key lifestyle and dietary risk factors in colorectal adenoma formation.
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Affiliation(s)
- Roman Corral
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
| | - Juan Pablo Lewinger
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
| | - Amit D. Joshi
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - A. Joan Levine
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- Division of Oncology, Department of Medicine, Stanford School of Medicine, Stanford, California, United States of America
| | - David J. Vandenberg
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
| | - Robert W. Haile
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- Division of Oncology, Department of Medicine, Stanford School of Medicine, Stanford, California, United States of America
| | - Mariana C. Stern
- Department of Preventive Medicine, Keck School of Medicine of USC, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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20
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Vallabhaneni H, O'Callaghan N, Sidorova J, Liu Y. Defective repair of oxidative base lesions by the DNA glycosylase Nth1 associates with multiple telomere defects. PLoS Genet 2013; 9:e1003639. [PMID: 23874233 PMCID: PMC3715427 DOI: 10.1371/journal.pgen.1003639] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 06/03/2013] [Indexed: 02/07/2023] Open
Abstract
Telomeres are chromosome end structures and are essential for maintenance of genome stability. Highly repetitive telomere sequences appear to be susceptible to oxidative stress-induced damage. Oxidation may therefore have a severe impact on telomere integrity and function. A wide spectrum of oxidative pyrimidine-derivatives has been reported, including thymine glycol (Tg), that are primarily removed by a DNA glycosylase, Endonuclease III-like protein 1 (Nth1). Here, we investigate the effect of Nth1 deficiency on telomere integrity in mice. Nth1 null (Nth1(-/-) ) mouse tissues and primary MEFs harbor higher levels of Endonuclease III-sensitive DNA lesions at telomeric repeats, in comparison to a non-telomeric locus. Furthermore, oxidative DNA damage induced by acute exposure to an oxidant is repaired slowly at telomeres in Nth1(-/-) MEFs. Although telomere length is not affected in the hematopoietic tissues of Nth1(-/-) adult mice, telomeres suffer from attrition and increased recombination and DNA damage foci formation in Nth1(-/-) bone marrow cells that are stimulated ex vivo in the presence of 20% oxygen. Nth1 deficiency also enhances telomere fragility in mice. Lastly, in a telomerase null background, Nth1(-/-) bone marrow cells undergo severe telomere loss at some chromosome ends and cell apoptosis upon replicative stress. These results suggest that Nth1 plays an important role in telomere maintenance and base repair against oxidative stress-induced base modifications. The fact that telomerase deficiency can exacerbate telomere shortening in Nth1 deficient mouse cells supports that base excision repair cooperates with telomerase to maintain telomere integrity.
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Affiliation(s)
- Haritha Vallabhaneni
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | | | - Julia Sidorova
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Yie Liu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
- * E-mail:
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21
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Bosshard M, Markkanen E, van Loon B. Base excision repair in physiology and pathology of the central nervous system. Int J Mol Sci 2012. [PMID: 23203191 PMCID: PMC3546685 DOI: 10.3390/ijms131216172] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Relatively low levels of antioxidant enzymes and high oxygen metabolism result in formation of numerous oxidized DNA lesions in the tissues of the central nervous system. Accumulation of damage in the DNA, due to continuous genotoxic stress, has been linked to both aging and the development of various neurodegenerative disorders. Different DNA repair pathways have evolved to successfully act on damaged DNA and prevent genomic instability. The predominant and essential DNA repair pathway for the removal of small DNA base lesions is base excision repair (BER). In this review we will discuss the current knowledge on the involvement of BER proteins in the maintenance of genetic stability in different brain regions and how changes in the levels of these proteins contribute to aging and the onset of neurodegenerative disorders.
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Affiliation(s)
- Matthias Bosshard
- Institute for Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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22
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Expression and purification of active mouse and human NEIL3 proteins. Protein Expr Purif 2012; 84:130-9. [PMID: 22569481 DOI: 10.1016/j.pep.2012.04.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 04/24/2012] [Accepted: 04/27/2012] [Indexed: 11/23/2022]
Abstract
Endonuclease VIII-like 3 (Neil3) is one of the five DNA glycosylases found in mammals that recognize and remove oxidized bases, and initiate the base excision repair (BER) pathway. Previous attempts to express and purify the mouse and human orthologs of Neil3 in their active form have not been successful. Here we report the construction of bicistronic expression vectors for expressing in Escherichia coli the full-length mouse Neil3 (MmuNeil3), its glycosylase domain (MmuNeil3Δ324), as well as the glycosylase domain of human Neil3 (NEIL3Δ324). The purified Neil3 proteins are all active, and NEIL3Δ324 exhibits similar glycosylase/lyase activity as MmuNeil3Δ324 on both single-stranded and double-stranded substrates containing thymine glycol (Tg), spiroiminodihydantoin (Sp) or an abasic site (AP). We show that N-terminal initiator methionine processing is critical for the activity of both mouse and human Neil3 proteins. Co-expressing an E. coli methionine aminopeptidase (EcoMap) Y168A variant with MmuNeil3, MmuNeil3Δ324 and NEIL3Δ324 improves the N-terminal methionine processing and increases the percentage of active Neil3 proteins in the preparation. The purified Neil3 proteins are suitable for biochemical, structural and functional studies.
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23
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Sampath H, McCullough AK, Lloyd RS. Regulation of DNA glycosylases and their role in limiting disease. Free Radic Res 2012; 46:460-78. [PMID: 22300253 DOI: 10.3109/10715762.2012.655730] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This review will present a current understanding of mechanisms for the initiation of base excision repair (BER) of oxidatively-induced DNA damage and the biological consequences of deficiencies in these enzymes in mouse model systems and human populations.
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Affiliation(s)
- Harini Sampath
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, Oregon 97239 - 3098, USA
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24
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Swartzlander DB, Bauer NC, Corbett AH, Doetsch PW. Regulation of base excision repair in eukaryotes by dynamic localization strategies. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:93-121. [PMID: 22749144 DOI: 10.1016/b978-0-12-387665-2.00005-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This chapter discusses base excision repair (BER) and the known mechanisms defined thus far regulating BER in eukaryotes. Unlike the situation with nucleotide excision repair and double-strand break repair, little is known about how BER is regulated to allow for efficient and accurate repair of many types of DNA base damage in both nuclear and mitochondrial genomes. Regulation of BER has been proposed to occur at multiple, different levels including transcription, posttranslational modification, protein-protein interactions, and protein localization; however, none of these regulatory mechanisms characterized thus far affect a large spectrum of BER proteins. This chapter discusses a recently discovered mode of BER regulation defined in budding yeast cells that involves mobilization of DNA repair proteins to DNA-containing organelles in response to genotoxic stress.
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Affiliation(s)
- Daniel B Swartzlander
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
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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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Gredilla R, Bohr VA, Stevnsner T. Mitochondrial DNA repair and association with aging--an update. Exp Gerontol 2010; 45:478-88. [PMID: 20096766 DOI: 10.1016/j.exger.2010.01.017] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 01/10/2010] [Accepted: 01/14/2010] [Indexed: 01/07/2023]
Abstract
Mitochondrial DNA is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible than nuclear DNA to oxidative damage. The accumulation of DNA damage is thought to play a critical role in the aging process and to be particularly deleterious in post-mitotic cells. Thus, DNA repair is an important mechanism for maintenance of genomic integrity. Despite the importance of mitochondria in the aging process, it was thought for many years that mitochondria lacked an enzymatic DNA repair system comparable to that in the nuclear compartment. However, it is now well established that DNA repair actively takes place in mitochondria. Oxidative DNA damage processing, base excision repair mechanisms were the first to be described in these organelles, and consequently the best understood. However, new proteins and novel DNA repair pathways, thought to be exclusively present in the nucleus, have recently been described also to be present in mitochondria. Here we review the main mitochondrial DNA repair pathways and their association with the aging process.
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Affiliation(s)
- Ricardo Gredilla
- Danish Center for Molecular Gerontology, Department of Molecular Biology, Aarhus University, C.F. Moellers allé 3, Aarhus C, Denmark
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27
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Hildrestrand GA, Duggal S, Bjørås M, Luna L, Brinchmann JE. Modulation of DNA glycosylase activities in mesenchymal stem cells. Exp Cell Res 2009; 315:2558-67. [PMID: 19477173 DOI: 10.1016/j.yexcr.2009.05.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/28/2009] [Accepted: 05/19/2009] [Indexed: 11/19/2022]
Abstract
Adipose-tissue derived mesenchymal stem cells (AT-MSCs) are a promising tool for use in cell-based therapies. However, in vitro expansion is required to obtain clinically relevant cell numbers, and this might increase the chance of genomic instability. DNA repair is crucial for maintaining DNA integrity. Here we have compared the initial step of base excision repair in uncultured and cultured AT-MSCs by analysis of base removal activities and expression levels of relevant DNA glycosylases. Uracil, 5-hydroxyuracil and ethenoadenine removal activities were upregulated in cultured cells compared to uncultured cells. In contrast, both the 8-oxo-7,8-dihydroguanine (8-oxoG) removal activity and the concentration of 8-oxoG bases in the DNA were reduced in the cultured cells. Gene expression analysis showed no substantial changes in mRNA expression. The glycosylase activities remained stable through at least 12 passages, suggesting that DNA repair is proficient through the period required for in vitro expansion of AT-MSCs to clinically relevant numbers.
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Affiliation(s)
- Gunn A Hildrestrand
- Centre for Molecular Biology and Neuroscience and Institute of Medical Microbiology, Rikshospitalet University Hospital, Oslo, Norway
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28
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Goto M, Shinmura K, Igarashi H, Kobayashi M, Konno H, Yamada H, Iwaizumi M, Kageyama S, Tsuneyoshi T, Tsugane S, Sugimura H. Altered expression of the human base excision repair gene NTH1 in gastric cancer. Carcinogenesis 2009; 30:1345-52. [DOI: 10.1093/carcin/bgp108] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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29
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Knudsen NØ, Andersen SD, Lützen A, Nielsen FC, Rasmussen LJ. Nuclear translocation contributes to regulation of DNA excision repair activities. DNA Repair (Amst) 2009; 8:682-9. [PMID: 19376751 DOI: 10.1016/j.dnarep.2009.03.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 03/06/2009] [Accepted: 03/14/2009] [Indexed: 11/26/2022]
Abstract
DNA mutations are circumvented by dedicated specialized excision repair systems, such as the base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR) pathways. Although the individual repair pathways have distinct roles in suppressing changes in the nuclear DNA, it is evident that proteins from the different DNA repair pathways interact [Y. Wang, D. Cortez, P. Yazdi, N. Neff, S.J. Elledge, J. Qin, BASC, a super complex of BRCA1-associated proteins involved in the recognition and repair of aberrant DNA structures, Genes Dev. 14 (2000) 927-939; M. Christmann, M.T. Tomicic, W.P. Roos, B. Kaina, Mechanisms of human DNA repair: an update, Toxicology 193 (2003) 3-34; N.B. Larsen, M. Rasmussen, L.J. Rasmussen, Nuclear and mitochondrial DNA repair: similar pathways? Mitochondrion 5 (2005) 89-108]. Protein interactions are not only important for function, but also for regulation of nuclear import that is necessary for proper localization of the repair proteins. This review summarizes the current knowledge on nuclear import mechanisms of DNA excision repair proteins and provides a model that categorizes the import by different mechanisms, including classical nuclear import, co-import of proteins, and alternative transport pathways. Most excision repair proteins appear to contain classical NLS sequences directing their nuclear import, however, additional import mechanisms add alternative regulatory levels to protein import, indirectly affecting protein function. Protein co-import appears to be a mechanism employed by the composite repair systems NER and MMR to enhance and regulate nuclear accumulation of repair proteins thereby ensuring faithful DNA repair.
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Affiliation(s)
- Nina Østergaard Knudsen
- Department of Science, Systems and Models, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark
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Krokeide SZ, Bolstad N, Laerdahl JK, Bjørås M, Luna L. Expression and purification of NEIL3, a human DNA glycosylase homolog. Protein Expr Purif 2008; 65:160-4. [PMID: 19121397 DOI: 10.1016/j.pep.2008.11.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 11/26/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
Abstract
The base excision repair (BER) pathway is mainly responsible for the repair of a vast number of non-bulky lesions produced by alkylation, oxidation or deamination of bases. DNA glycosylases are the key enzymes that recognize damaged bases and initiate BER by catalyzing the cleavage of the N-glycosylic bond between the base and the sugar. Many of the mammalian DNA glycosylases have been identified by a combination of biochemical and bioinformatics analysis. Thus, a mammalian family of three proteins (NEIL1, NEIL2 and NEIL3) that showed homology to the Escherichia coli Fpg/Nei DNA glycosylases was identified. Two of the proteins, NEIL1 and NEIL2 have been thoroughly characterized and shown to initiate BER of a diverse number of oxidized lesions. However, much less is known about NEIL3. The biochemical properties of NEIL3 have not been elucidated. This is mainly due to the difficulty in the expression and purification of NEIL3. Here, we describe the expression and partial purification of full-length human NEIL3 and the expression, purification and characterization of a truncated human core-NEIL3 (amino acids 1-301) that contains the complete E. coli Fpg/Nei-like domain but lacks the C-terminal region.
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Affiliation(s)
- Silje Z Krokeide
- Centre for Molecular Biology and Neuroscience, Department of Molecular Biology, Institute of Microbiology, Rikshospitalet Medical Centre, Sognsvannsveien 28, N0027 Oslo, Norway
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de Souza-Pinto NC, Wilson DM, Stevnsner TV, Bohr VA. Mitochondrial DNA, base excision repair and neurodegeneration. DNA Repair (Amst) 2008; 7:1098-109. [PMID: 18485834 DOI: 10.1016/j.dnarep.2008.03.011] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neurodegeneration is a growing public health concern because of the rapid increase in median and maximum life expectancy in the developed world. Mitochondrial dysfunction seems to play a critical role in neurodegeneration, likely owing to the high energy demand of the central nervous system and its sole reliance on oxidative metabolism for energy production. Loss of mitochondrial function has been clearly demonstrated in several neuropathologies, most notably those associated with age, like Alzheimer's, Parkinson's and Huntington's diseases. Among the common features observed in such conditions is the accumulation of oxidative DNA damage, in particular in the mitochondrial DNA, suggesting that mitochondrial DNA instability may play a causative role in the development of these diseases. In this review we examine the evidence for the accumulation of oxidative DNA damage in mitochondria, and its relationship with loss of mitochondrial function and cell death in neural tissues. Oxidative DNA damage is repaired mainly by the base excision repair pathway. Thus, we review the molecular events and enzymes involved in base excision repair in mitochondria, and explore the possible role of alterations in mitochondrial base excision repair activities in premature aging and age-associated neurodegenerative diseases.
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Affiliation(s)
- Nadja C de Souza-Pinto
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21224, USA
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Chaudhry MA. Base excision repair of ionizing radiation-induced DNA damage in G1 and G2 cell cycle phases. Cancer Cell Int 2007; 7:15. [PMID: 17892593 PMCID: PMC2063494 DOI: 10.1186/1475-2867-7-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 09/24/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Major genomic surveillance mechanisms regulated in response to DNA damage exist at the G1/S and G2/M checkpoints. It is presumed that these delays provide time for the repair of damaged DNA. Cells have developed multiple DNA repair pathways to protect themselves from different types of DNA damage. Oxidative DNA damage is processed by the base excision repair (BER) pathway. Little is known about the BER of ionizing radiation-induced DNA damage and putative heterogeneity of BER in the cell cycle context. We measured the activities of three BER enzymes throughout the cell cycle to investigate the cell cycle-specific repair of ionizing radiation-induced DNA damage. We further examined BER activities in G2 arrested human cells after exposure to ionizing radiation. RESULTS Using an in vitro incision assay involving radiolabeled oligonucleotides with specific DNA lesions, we examined the activities of several BER enzymes in the whole cell extracts prepared from synchronized human HeLa cells irradiated in G1 and G2 phase of the cell cycle. The activities of human endonuclease III (hNTH1), a glycosylase/lyase that removes several damaged bases from DNA including dihydrouracil (DHU), 8-oxoguanine-DNA glycosylase (hOGG1) that recognizes 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxoG) lesion and apurinic/apyrimidinic endonuclease (hAPE1) that acts on abasic sites including synthetic analog furan were examined. CONCLUSION Overall the repair activities of hNTH1 and hAPE1 were higher in the G1 compared to G2 phase of the cell cycle. The percent cleavages of oligonucleotide substrate with furan were greater than substrate with DHU in both G1 and G2 phases. The irradiation of cells enhanced the cleavage of substrates with furan and DHU only in G1 phase. The activity of hOGG1 was much lower and did not vary within the cell cycle. These results demonstrate the cell cycle phase dependence on the BER of ionizing radiation-induced DNA damage. Interestingly no evidence of enhanced BER activities was found in irradiated cells arrested in G2 phase.
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Affiliation(s)
- M Ahmad Chaudhry
- Department of Medical Laboratory and Radiation Sciences, University of Vermont, Burlington, VT 05405, USA.
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Ranneberg-Nilsen T, Bjørås M, Luna L, Slettebakk R, Dale HA, Seeberg E, Rollag H. Human cytomegalovirus infection modulates DNA base excision repair in fibroblast cells. Virology 2006; 348:389-97. [PMID: 16476462 DOI: 10.1016/j.virol.2006.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2005] [Revised: 09/26/2005] [Accepted: 01/03/2006] [Indexed: 10/25/2022]
Abstract
Regulation of DNA repair mechanisms during the viral replication cycle may have consequences for the virus with regards to genomic variability, adaptation, and replication of viral DNA. We have studied the activities and expression patterns of key enzymes involved in the first two steps of base excision repair (BER) of DNA in primary fibroblasts infected by human cytomegalovirus (HCMV). Infected cells were very proficient for removal of uracil and 5' hydrolysis of AP sites (AP endonuclease activity) as compared to the mock-infected cells, suggesting a direct role in generating free ends at uracil lesions in DNA for initiation of viral replication. Furthermore, the capacity to initiate repair of alkylated and oxidized base lesions were reduced in HCMV-infected cells, indicating increased mutation frequencies that could promote genetic variability. We hypothesize that modulation of BER activities may play an important role in HCMV pathogenesis to ensure efficient replication and genomic variation of viral DNA.
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Affiliation(s)
- Toril Ranneberg-Nilsen
- Department of Virology, Institute of Microbiology, University of Oslo, Rikshospitalet, Norway.
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Meira LB, Burgis NE, Samson LD. Base excision repair. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 570:125-73. [PMID: 18727500 DOI: 10.1007/1-4020-3764-3_5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Lisiane B Meira
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Hu J, de Souza-Pinto NC, Haraguchi K, Hogue BA, Jaruga P, Greenberg MM, Dizdaroglu M, Bohr VA. Repair of formamidopyrimidines in DNA involves different glycosylases: role of the OGG1, NTH1, and NEIL1 enzymes. J Biol Chem 2005; 280:40544-51. [PMID: 16221681 DOI: 10.1074/jbc.m508772200] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The oxidatively induced DNA lesions 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG) and 4,6-diamino-5-formamidopyrimidine (FapyA) are formed abundantly in DNA of cultured cells or tissues exposed to ionizing radiation or to other free radical-generating systems. In vitro studies indicate that these lesions are miscoding, can block the progression of DNA polymerases, and are substrates for base excision repair. However, no study has yet addressed how these lesions are metabolized in cellular extracts. The synthesis of oligonucleotides containing FapyG and FapyA at defined positions was recently reported. These constructs allowed us to investigate the repair of Fapy lesions in nuclear and mitochondrial extracts from wild type and knock-out mice lacking the two major DNA glycosylases for repair of oxidative DNA damage, OGG1 and NTH1. The background level of FapyG/FapyA in DNA from these mice was also determined. Endogenous FapyG levels in liver DNA from wild type mice were significantly higher than 8-hydroxyguanine levels. FapyG and FapyA were efficiently repaired in nuclear and mitochondrial extracts from wild type animals but not in the glycosylase-deficient mice. Our results indicated that OGG1 and NTH1 are the major DNA glycosylases for the removal of FapyG and FapyA, respectively. Tissue-specific analysis suggested that other DNA glycosylases may contribute to FapyA repair when NTH1 is poorly expressed. We identified NEIL1 in liver mitochondria, which could account for the residual incision activity in the absence of OGG1 and NTH1. FapyG and FapyA levels were significantly elevated in DNA from the knock-out mice, underscoring the biological role of OGG1 and NTH1 in the repair of these lesions.
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Affiliation(s)
- Jingping Hu
- Laboratory of Molecular Gerontology, NIA, National Institutes of Health, Baltimore, Maryland 21224, USA
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37
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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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O'reilly MA, Vitiello PF, Gehen SC, Staversky RJ. p21(Cip1/WAF1/Sdi1) does not affect expression of base excision DNA repair enzymes during chronic oxidative stress. Antioxid Redox Signal 2005; 7:719-25. [PMID: 15890018 DOI: 10.1089/ars.2005.7.719] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Exposure to chronic oxidative stress during elevated oxygen (hyperoxia) damages DNA and inhibits cell proliferation in G(1) through induction of the cyclin-dependent kinase inhibitor p21. Cells that fail to express p21 growth-arrest in S phase. The observation that growth arrest in G(1) is associated with reduced DNA damage and enhanced survival suggests that p21 may affect expression of base excision repair (BER) enzymes used to repair oxidized DNA. This hypothesis was tested in p21 wild-type and p21-deficient mice and human lung adenocarcinoma H1299 cells with tetracycline-on regulated expression of p21. The mRNA levels of Ogg1, Tdg, Udg, Mpg, Nth1, and Mgmt remained constant during 3 days of hyperoxia. The expression of Ogg1, Nth1, and APE protein also remained unchanged. Although hyperoxia increased p21, its absence did not significantly affect expression of these repair enzymes. These findings reveal that hyperoxia induces p21 without significantly altering BER enzyme expression. This suggests that p21 may protect oxidized cells by affecting the activity of BER enzymes and/or through other mechanisms, such as apoptosis.
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Affiliation(s)
- Michael A O'reilly
- Department of Pediatrics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
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40
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Kim SH, Lee JY, Kim J. Characterization of a wide range base-damage-endonuclease activity of mammalian rpS3. Biochem Biophys Res Commun 2005; 328:962-7. [PMID: 15707971 DOI: 10.1016/j.bbrc.2005.01.045] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Indexed: 11/17/2022]
Abstract
Mammalian rpS3, a ribosomal protein S3 with a DNA repair endonuclease activity, nicks heavily UV-irradiated DNA and DNA containing AP sites. RpS3 calls for a novel endonucleolytic activity on AP sites generated from pyrimidine dimers by T4 pyrimidine dimer glycosylase activity. This study revealed that rpS3 cleaves the lesions including AP sites, thymine glycols, and other UV damaged lesions such as pyrimidine dimers. This enzyme does not have a glycosylase activity as predicted from its amino acid sequence. However, it has an endonuclease activity on DNA containing thymine glycol, which is exactly overlapped with UV-irradiated or AP DNAs, indicating that rpS3 cleaves phosphodiester bonds of DNAs containing altered bases with broad specificity acting as a base-damage-endonuclease. RpS3 cleaves supercoiled UV damaged DNA more efficiently than the relaxed counterpart, and the endonuclease activity of rpS3 was inhibited by MgCl2 on AP DNA but not on UV-irradiated DNA.
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Affiliation(s)
- Sang Hwa Kim
- Laboratory of Biochemistry, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea
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41
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Luna L, Rolseth V, Hildrestrand GA, Otterlei M, Dantzer F, Bjørås M, Seeberg E. Dynamic relocalization of hOGG1 during the cell cycle is disrupted in cells harbouring the hOGG1-Cys326 polymorphic variant. Nucleic Acids Res 2005; 33:1813-24. [PMID: 15800211 PMCID: PMC1072800 DOI: 10.1093/nar/gki325] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Numerous lines of evidence support the role of oxidative stress in different types of cancer. A major DNA lesion, 8-oxo-7,8-dihydroguanine (8-oxoG), is formed by reactive oxygen species in the genome under physiological conditions. 8-OxoG is strongly mutagenic, generating G·C→T·A transversions, a frequent somatic mutation in cancers. hOGG1 was cloned as a gene encoding a DNA glycosylase that specifically recognizes and removes 8-oxoG from 8-oxoG:C base pairs and suppresses G·C→T·A transversions. In this study, we investigated the subcellular localization and expression of hOGG1 during the cell cycle. Northern blots showed cell-cycle-dependent mRNA expression of the two major hOGG1 isoforms. By using a cell line constitutively expressing hOGG1 fused to enhanced green fluorescence protein (EGFP), we observed a dynamic relocalization of EGFP-hOGG1 to the nucleoli during the S-phase of the cell cycle, and this localization was shown to be linked to transcription. A C/G change that results in an amino acid substitution from serine to cysteine in codon 326 has been reported as a genetic polymorphism and a risk allele for a variety of cancers. We investigated the cellular localization of the corresponding protein, hOGG1-Cys326, fused to EGFP and observed a dramatic effect on its localization that is explained by a change in the phosphorylation status of hOGG1.
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Affiliation(s)
- Luisa Luna
- Centre for Molecular Biology and Neuroscience, Institute of Medical Microbiology, University of Oslo Rikshospitalet, N-0027 Oslo, Norway.
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42
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Impaired base excision repair and accumulation of oxidative base lesions in CD4+ T cells of HIV-infected patients. Blood 2005; 105:4730-5. [PMID: 15705786 DOI: 10.1182/blood-2004-11-4272] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Several studies have reported enhanced oxidative stress in patients with HIV infection. An important pathophysiologic consequence of increased oxidative stress is endogenous DNA damage, and the base excision repair pathway is the most important mechanism to withstand such deleterious effects. To investigate the role of base excision repair in HIV infection, we examined 7,8-dihydro-8-oxoguanine (8-oxoG) levels as a marker of oxidative DNA damage and DNA glycosylase activities in CD4(+) and CD8(+) T cells of HIV-infected patients and controls. These results showed that the HIV-infected patients, particularly those with advanced disease, had increased levels of 8-oxoG in CD4(+) T cells and marked declines in DNA glycosylase activity for the repair of oxidative base lesions in these cells. In contrast, CD8(+) T cells from HIV-infected patients, with 8-oxoG levels similar to those in healthy controls, showed enhanced capacity to repair oxidative DNA damage. Finally, highly active antiretroviral therapy induced increased glycosylase activity in CD4(+) T cells and normalized 8-oxoG levels. This imbalance between the accumulation of oxidative DNA damage and the capacity to repair such lesions in CD4(+) T cells may represent a previously unrecognized mechanism involved in the numerical and functional impairment of CD4(+) T cells in patients with HIV infection.
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Oyama M, Wakasugi M, Hama T, Hashidume H, Iwakami Y, Imai R, Hoshino S, Morioka H, Ishigaki Y, Nikaido O, Matsunaga T. Human NTH1 physically interacts with p53 and proliferating cell nuclear antigen. Biochem Biophys Res Commun 2004; 321:183-91. [PMID: 15358233 DOI: 10.1016/j.bbrc.2004.06.136] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Indexed: 11/22/2022]
Abstract
Thymine glycol (Tg) is one of predominant oxidative DNA lesions caused by ionizing radiation and other oxidative stresses. Human NTH1 is a bifunctional enzyme with DNA glycosylase and AP lyase activities and removes Tg as the first step of base excision repair (BER). We have searched for the factors interacting with NTH1 by using a pull-down assay and found that GST-NTH1 fusion protein precipitates proliferating cell nuclear antigen (PCNA) and p53 as well as XPG from human cell-free extracts. GST-NTH1 also bound to recombinant FLAG-tagged XPG, PCNA, and (His)6-tagged p53 proteins, indicating direct protein-protein interaction between those proteins. Furthermore, His-p53 and FLAG-XPG, but not PCNA, stimulated the Tg DNA glycosylase/AP lyase activity of GST-NTH1 or NTH1. These results provide an insight into the positive regulation of BER reaction and also suggest a possible linkage between BER of Tg and other cellular mechanisms.
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Affiliation(s)
- Masaki Oyama
- Laboratory of Molecular Human Genetics, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
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Evans MD, Dizdaroglu M, Cooke MS. Oxidative DNA damage and disease: induction, repair and significance. MUTATION RESEARCH/REVIEWS IN MUTATION RESEARCH 2004; 567:1-61. [PMID: 15341901 DOI: 10.1016/j.mrrev.2003.11.001] [Citation(s) in RCA: 878] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Revised: 11/12/2003] [Accepted: 11/12/2003] [Indexed: 04/08/2023]
Abstract
The generation of reactive oxygen species may be both beneficial to cells, performing a function in inter- and intracellular signalling, and detrimental, modifying cellular biomolecules, accumulation of which has been associated with numerous diseases. Of the molecules subject to oxidative modification, DNA has received the greatest attention, with biomarkers of exposure and effect closest to validation. Despite nearly a quarter of a century of study, and a large number of base- and sugar-derived DNA lesions having been identified, the majority of studies have focussed upon the guanine modification, 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-OH-dG). For the most part, the biological significance of other lesions has not, as yet, been investigated. In contrast, the description and characterisation of enzyme systems responsible for repairing oxidative DNA base damage is growing rapidly, being the subject of intense study. However, there remain notable gaps in our knowledge of which repair proteins remove which lesions, plus, as more lesions identified, new processes/substrates need to be determined. There are many reports describing elevated levels of oxidatively modified DNA lesions, in various biological matrices, in a plethora of diseases; however, for the majority of these the association could merely be coincidental, and more detailed studies are required. Nevertheless, even based simply upon reports of studies investigating the potential role of 8-OH-dG in disease, the weight of evidence strongly suggests a link between such damage and the pathogenesis of disease. However, exact roles remain to be elucidated.
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Affiliation(s)
- Mark D Evans
- Oxidative Stress Group, Department of Clinical Biochemistry, University of Leicester, Leicester Royal Infirmary, University Hospitals of Leicester NHS Trust, LE2 7LX, UK
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45
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Rachek LI, Grishko VI, Alexeyev MF, Pastukh VV, LeDoux SP, Wilson GL. Endonuclease III and endonuclease VIII conditionally targeted into mitochondria enhance mitochondrial DNA repair and cell survival following oxidative stress. Nucleic Acids Res 2004; 32:3240-7. [PMID: 15199172 PMCID: PMC434452 DOI: 10.1093/nar/gkh648] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial DNA (mtDNA) is exposed to reactive oxygen species (ROS) produced during oxidative phosphorylation. Accumulation of several kinds of oxidative lesions, including oxidized pyrimidines, in mtDNA may lead to structural genomic alterations, mitochondrial dysfunction and associated degenerative diseases. In Escherichia coli, oxidative pyrimidines are repaired by endonuclease III (EndoIII) and endonuclease VIII (EndoVIII). To determine whether the overexpression of two bacterial glycosylase/AP lyases which predominantly remove oxidized pyrimidines from DNA, could improve mtDNA repair and cell survival, we constructed vectors containing sequences for the EndoIII and EndoVIII downstream of the mitochondrial targeting sequence (MTS) from manganese superoxide dismutase (MnSOD) and placed them under the control of the tetracycline (Tet)-response element. Successful integrations of MTS-EndoIII or MTS-EndoVIII into the HeLa Tet-On genome were confirmed by Southern blot. Western blots of mitochondrial extracts from MTS-EndoIII and MTS-EndoVIII clones revealed that the recombinant proteins are targeted into mitochondria and their expressions are doxycycline (Dox) dependent. Enzyme activity assays and mtDNA repair studies showed that the Dox-dependent expressions of MTS-EndoIII and MTS-EndoVIII are functional, and both MTS-EndoIII and MTS-EndoVIII (Dox+) clones were significantly more proficient at repair of oxidative damage in their mtDNA. This enhanced repair led to increased cellular resistance to oxidative stress.
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Affiliation(s)
- Lyudmila I Rachek
- Department of Cell Biology and Neuroscience, College of Medicine, University of South Alabama, Mobile, AL 36688, USA
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46
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Inoue M, Shen GP, Chaudhry MA, Galick H, Blaisdell JO, Wallace SS. Expression of the oxidative base excision repair enzymes is not induced in TK6 human lymphoblastoid cells after low doses of ionizing radiation. Radiat Res 2004; 161:409-17. [PMID: 15038771 DOI: 10.1667/3163] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Most of the DNA damage produced by ionizing radiation is repaired by the base excision repair (BER) pathway. To determine whether the BER genes were up-regulated by low doses of ionizing radiation, we investigated their expression in TK6 human lymphoblastoid cells by measuring mRNA levels using real-time quantitative PCR. No induction at the transcriptional level of any of the base excision repair genes, NTH1 (NTHL1), OGG1, NEIL1, NEIL2, NEIL3, APE1, POLB, or accessory protein genes, LIG3, XRCC1 or XPG, was found at gamma-radiation doses ranging from 1 cGy to 2 Gy in a 24-h period. As has been measured in other cell lines, a dose-dependent induction of CDKN1A (WAF1) mRNA levels was observed in TK6 cells in the dose range of 0.5 to 2.0 Gy. We also examined BER enzyme activity on 8-oxoguanine-, dihydrouracil- and furan-containing oligonucleotide substrates and found no increase in extracts of TK6 cells after gamma-ray doses of 0.5-2.0 Gy. These data were corroborated by Western blot analysis of APE1 and NTH1, suggesting that the BER enzymes are also not up-regulated at the post-transcriptional level after ionizing radiation exposure.
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Affiliation(s)
- M Inoue
- Department of Microbiology and Molecular Genetics, The Markey Center for Molecular Genetics, The University of Vermont, Burlington, Vermont 05405-0068, USA
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Miller H, Fernandes AS, Zaika E, McTigue MM, Torres MC, Wente M, Iden CR, Grollman AP. Stereoselective excision of thymine glycol from oxidatively damaged DNA. Nucleic Acids Res 2004; 32:338-45. [PMID: 14726482 PMCID: PMC373299 DOI: 10.1093/nar/gkh190] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
DNA damage created by reactive oxygen species includes the prototypic oxidized pyrimidine, thymine glycol (Tg), which exists in oxidatively damaged DNA as two diastereoisomeric pairs. In Escherichia coli, Saccharomyces cerevesiae and mice, Tg is preferentially excised by endonuclease III (Endo III) and endonuclease VIII (Endo VIII), yNTG1 and yNTG2, and mNTH and mNEIL1, respectively. We have explored the ability of these DNA glycosylases to discriminate between Tg stereoisomers. Oligonucleotides containing a single, chromatographically pure (5S,6R) or (5R,6S) stereoisomer of Tg were prepared by oxidation with osmium tetroxide. Steady-state kinetic analyses of the excision process revealed that Endo III, Endo VIII, yNTG1, mNTH and mNEIL1, but not yNTG2, excise Tg isomers from DNA in a stereoselective manner, as reflected in the parameter of catalytic efficiency (kcat/Km). When DNA glycosylases occur as complementary pairs, failure of one or both enzymes to excise their cognate Tg stereoisomer from oxidatively damaged DNA could have deleterious consequences for the cell.
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Affiliation(s)
- Holly Miller
- Laboratory of Chemical Biology, State University of New York, Stony Brook, NY, USA.
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48
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Karahalil B, de Souza-Pinto NC, Parsons JL, Elder RH, Bohr VA. Compromised incision of oxidized pyrimidines in liver mitochondria of mice deficient in NTH1 and OGG1 glycosylases. J Biol Chem 2003; 278:33701-7. [PMID: 12819227 DOI: 10.1074/jbc.m301617200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial DNA is constantly exposed to high levels of endogenously produced reactive oxygen species, resulting in elevated levels of oxidative damaged DNA bases. A large spectrum of DNA base alterations can be detected after oxidative stress, and many of these are highly mutagenic. Thus, an efficient repair of these is necessary for survival. Some of the DNA repair pathways involved have been characterized, but others are not yet determined. A DNA repair activity for thymine glycol and other oxidized pyrimidines has been described in mammalian mitochondria, but the nature of the glycosylases involved in this pathway remains unclear. The generation of mouse strains lacking murine thymine glycol-DNA glycosylase (mNTH1) and/or murine 8-oxoguanine-DNA glycosylase (mOGG1), the two major DNA N-glycosylase/apurinic/apyrimidinic (AP) lyases involved in the repair of oxidative base damage in the nucleus, has provided very useful biological model systems for the study of the function of these and other glycosylases in mitochondrial DNA repair. In this study, mouse liver mitochondrial extracts were generated from mNTH1-, mOGG1-, and [mNTH1, mOGG1]-deficient mice to ascertain the role of each of these glycosylases in the repair of oxidized pyrimidine base damage. We also characterized for the first time the incision of various modified bases in mitochondrial extracts from a double-knock-out [mNTH1, mOGG1]-deficient mouse. We show that mNTH1 is responsible for the repair of thymine glycols in mitochondrial DNA, whereas other glycosylase/AP lyases also participate in removing other oxidized pyrimidines, such as 5-hydroxycytosine and 5-hydroxyuracil. We did not detect a backup glycosylase or glycosylase/AP lyase activity for thymine glycol in the mitochondrial mouse extracts.
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Affiliation(s)
- Bensu Karahalil
- Laboratory of Molecular Gerontology, National Institute on Aging,, National Institutes of Health, Baltimore, Maryland 21224, USA
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Abstract
Oxidative DNA damage is an inevitable consequence of cellular metabolism, with a propensity for increased levels following toxic insult. Although more than 20 base lesions have been identified, only a fraction of these have received appreciable study, most notably 8-oxo-2'deoxyguanosine. This lesion has been the focus of intense research interest and been ascribed much importance, largely to the detriment of other lesions. The present work reviews the basis for the biological significance of oxidative DNA damage, drawing attention to the multiplicity of proteins with repair activities along with a number of poorly considered effects of damage. Given the plethora of (often contradictory) reports describing pathological conditions in which levels of oxidative DNA damage have been measured, this review critically addresses the extent to which the in vitro significance of such damage has relevance for the pathogenesis of disease. It is suggested that some shortcomings associated with biomarkers, along with gaps in our knowledge, may be responsible for the failure to produce consistent and definitive results when applied to understanding the role of DNA damage in disease, highlighting the need for further studies.
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Affiliation(s)
- Marcus S Cooke
- Oxidative Stress Group, Department of Clinical Biochemistry, University of Leicester, Leicester Royal Infirmary, University Hospitals of Leicester NHS Trust, Leicester, LE2 7LX, UK.
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Rosenquist TA, Zaika E, Fernandes AS, Zharkov DO, Miller H, Grollman AP. The novel DNA glycosylase, NEIL1, protects mammalian cells from radiation-mediated cell death. DNA Repair (Amst) 2003; 2:581-91. [PMID: 12713815 DOI: 10.1016/s1568-7864(03)00025-9] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
DNA damage mediated by reactive oxygen species generates miscoding and blocking lesions that may lead to mutations or cell death. Base excision repair (BER) constitutes a universal mechanism for removing oxidatively damaged bases and restoring the integrity of genomic DNA. In Escherichia coli, the DNA glycosylases Nei, Fpg, and Nth initiate BER of oxidative lesions; OGG1 and NTH1 proteins fulfill a similar function in mammalian cells. Three human genes, designated NEIL1, NEIL2 and NEIL3, encode proteins that contain sequence homologies to Nei and Fpg. We have cloned the corresponding mouse genes and have overexpressed and purified mNeil1, a DNA glycosylase that efficiently removes a wide spectrum of mutagenic and cytotoxic DNA lesions. These lesions include the two cis-thymineglycol(Tg) stereoisomers, guanine- and adenine-derived formamidopyrimidines, and 5,6-dihydrouracil. Two of these lesions, fapyA and 5S,6R thymine glycol, are not excised by mOgg1 or mNth1. We have also used RNA interference technology to establish embryonic stem cell lines deficient in Neil1 protein and showed them to be sensitive to low levels of gamma-irradiation. The results of these studies suggest that Neil1 is an essential component of base excision repair in mammalian cells; its presence may contribute to the redundant repair capacity observed in Ogg1 -/- and Nth1 -/- mice.
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Affiliation(s)
- Thomas A Rosenquist
- Department of Pharmacological Sciences, SUNY Stony Brook, Stony Brook, NY 11794, USA.
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