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Chang TT, Lin LY, Chen C, Chen JW. CCL4 contributes to aging related angiogenic insufficiency through activating oxidative stress and endothelial inflammation. Angiogenesis 2024; 27:475-499. [PMID: 38739303 PMCID: PMC11303582 DOI: 10.1007/s10456-024-09922-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Accepted: 04/15/2024] [Indexed: 05/14/2024]
Abstract
Aging is a natural process associated with chronic inflammation in the development of vascular dysfunction. We hypothesized that chemokine C-C motif ligands 4 (CCL4) might play a vital role in aging-related vascular dysfunction. Circulating CCL4 was up-regulated in elderly subjects and in aged animals. CCL4 inhibition reduced generation of reactive oxygen species (ROS), attenuated inflammation, and restored cell functions in endothelial progenitor cells from elderly subjects and in aged human aortic endothelial cells. CCL4 promoted cell aging, with impaired cell functioning, by activating ROS production and inflammation. CCL4 knockout mice and therapeutic administration of anti-CCL4 neutralizing antibodies exhibited vascular and dermal anti-aging effects, with improved wound healing, via the down-regulation of inflammatory proteins and the activation of angiogenic proteins. Altogether, our findings suggested that CCL4 may contribute to aging-related vascular dysfunction via activating oxidative stress and endothelial inflammation. CCL4 may be a potential therapeutic target for vascular protections during aging.
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Affiliation(s)
- Ting-Ting Chang
- Department and Institute of Pharmacology, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Biomedical Industry Ph.D. Program, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Cardiovascular Research Center, Taipei Medical University Hospital and Taipei Medical University, Taipei, Taiwan.
- Department and Institute of Pharmacology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
| | - Liang-Yu Lin
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Division of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ching Chen
- Department and Institute of Pharmacology, National Yang Ming Chiao Tung University, Taipei, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jaw-Wen Chen
- Department and Institute of Pharmacology, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Cardiovascular Research Center, Taipei Medical University Hospital and Taipei Medical University, Taipei, Taiwan.
- Division of Cardiology, Department of Medicine, Department of Research, Taipei Medical University Hospital, Taipei, Taiwan.
- Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
- Cardiovascular Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan.
- Department of Research, Taipei Medical University Hospital, Taipei, Taiwan.
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2
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Associations of Dynapenic Obesity and Sarcopenic Obesity with the Risk of Complications in COVID-19. Int J Mol Sci 2022; 23:ijms23158277. [PMID: 35955411 PMCID: PMC9368708 DOI: 10.3390/ijms23158277] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 02/07/2023] Open
Abstract
Ageing is associated with changes in body composition, such as low muscle mass (sarcopenia), decreased grip strength or physical function (dynapenia), and accumulation of fat mass. When the accumulation of fat mass synergistically accompanies low muscle mass or reduced grip strength, it results in sarcopenic obesity and dynapenic obesity, respectively. These types of obesity contribute to the increased risk of cardiovascular disease and mortality in the elderly, which could increase the damage caused by COVID-19. In this review, we associated factors that could generate a higher risk of COVID-19 complications in dynapenic obesity and sarcopenic obesity. For example, skeletal muscle regulates the expression of inflammatory cytokines and supports metabolic stress in pulmonary disease; hence, the presence of dynapenic obesity or sarcopenic obesity could be related to a poor prognosis in COVID-19 patients.
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SIPS as a model to study age-related changes in proteolysis and aggregate formation. Mech Ageing Dev 2017; 170:72-81. [PMID: 28755850 DOI: 10.1016/j.mad.2017.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/07/2017] [Accepted: 07/20/2017] [Indexed: 01/21/2023]
Abstract
Aging is accompanied by the accumulation of cellular damage over time in response to stress, lifestyle and environmental factors ultimately leading to age-related diseases and death. Additionally, the number of senescent cells increases with age. Senescence is most likely not a static endpoint, it represents a series of hallmarks including morphological changes, alterations in protein turnover and accumulation of protein aggregates. The importance of protein oxidation and aggregate accumulation in the progression of aging is not yet fully understood and research to what extent the accumulation of oxidized proteins has an effect on senescence and the aging process is still ongoing. To study the mechanisms of aging, the impact of senescence and the role of protein aggregates on the aging process, cell culture models are useful tools. Most notably stress induced premature senescence (SIPS) models have contributed to the identification of mechanisms involved in the aging process and helped unravel the age-related changes in proteolysis and the importance of protein aggregation. Here we review characteristics of replicative and premature senescence, how to induce most frequently used senescence models and gained knowledge on age-related changes in the major proteolytic systems.
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4
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Pathophysiology of bronchoconstriction: role of oxidatively damaged DNA repair. Curr Opin Allergy Clin Immunol 2016; 16:59-67. [PMID: 26694039 DOI: 10.1097/aci.0000000000000232] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW To provide an overview on the present understanding of roles of oxidative DNA damage repair in cell signaling underlying bronchoconstriction common to, but not restricted to various forms of asthma and chronic obstructive pulmonary disease. RECENT FINDINGS Bronchoconstriction is a tightening of smooth muscle surrounding the bronchi and bronchioles with consequent wheezing and shortness of breath. Key stimuli include air pollutants, viral infections, allergens, thermal and osmotic changes, and shear stress of mucosal epithelium, triggering a wide range of cellular, vascular, and neural events. Although activation of nerve fibers, the role of G-proteins, protein kinases and Ca++, and molecular interaction within contracting filaments of muscle are well defined, the overarching mechanisms by which a wide range of stimuli initiate these events are not fully understood. Many, if not all, stimuli increase levels of reactive oxygen species, which are signaling and oxidatively modifying macromolecules, including DNA. The primary reactive oxygen species target in DNA is guanine, and 8-oxoguanine is one of the most abundant base lesions. It is repaired by 8-oxoguanine DNA glycosylase1 during base excision repair processes. The product, free 8-oxo-7,8-dihydro-2'-deoxyguanosine base, is bound by 8-oxoguanine DNA glycosylase1 with high affinity, and the complex then functions as an activator of small guanosine triphosphatases, triggering pathways for inducing gene expression and contraction of intracellular filaments in mast and smooth muscle cells. SUMMARY Oxidative DNA damage repair-mediated cell activation signaling result in gene expression that 'primes' the mucosal epithelium and submucosal tissues to generate mediators of airway smooth muscle contractions.
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Xu Z, Zhang L, Zhang W, Meng D, Zhang H, Jiang Y, Xu X, Van Meter M, Seluanov A, Gorbunova V, Mao Z. SIRT6 rescues the age related decline in base excision repair in a PARP1-dependent manner. Cell Cycle 2015; 14:269-76. [PMID: 25607651 DOI: 10.4161/15384101.2014.980641] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In principle, a decline in base excision repair (BER) efficiency with age should lead to genomic instability and ultimately contribute to the onset of the aging phenotype. Although multiple studies have indicated a negative link between aging and BER, the change of BER efficiency with age in humans has not been systematically analyzed. Here, with foreskin fibroblasts isolated from 19 donors between 20 and 64 y of age, we report a significant decline of BER efficiency with age using a newly developed GFP reactivation assay. We further observed a very strong negative correlation between age and the expression levels of SIRT6, a factor which is known to maintain genomic integrity by improving DNA double strand break (DSB) repair. Our mechanistic study suggests that, similar to the regulatory role that SIRT6 plays in DNA DSB repair, SIRT6 regulates BER in a PARP1-depdendent manner. Moreover, overexpression of SIRT6 rescues the decline of BER in aged fibroblasts. In summary, our results uncovered the regulatory mechanisms of BER by SIRT6, suggesting that SIRT6 reactivation in aging tissues may help delay the process of aging through improving BER.
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Affiliation(s)
- Zhu Xu
- a Department of Clinical Laboratory Medicine; Shanghai Tenth People's Hospital; School of Life Sciences and Technology; Tongji University ; Shanghai , China
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6
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Abstract
Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.
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Moor AN, Tummel E, Prather JL, Jung M, Lopez JJ, Connors S, Gould LJ. Consequences of age on ischemic wound healing in rats: altered antioxidant activity and delayed wound closure. AGE (DORDRECHT, NETHERLANDS) 2014; 36:733-48. [PMID: 24443098 PMCID: PMC4039282 DOI: 10.1007/s11357-014-9617-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 01/07/2014] [Indexed: 05/12/2023]
Abstract
Advertisements targeted at the elderly population suggest that antioxidant therapy will reduce free radicals and promote wound healing, yet few scientific studies substantiate these claims. To better understand the potential utility of supplemental antioxidant therapy for wound healing, we tested the hypothesis that age and tissue ischemia alter the balance of endogenous antioxidant enzymes. Using a bipedicled skin flap model, ischemic and non-ischemic wounds were created on young and aged rats. Wound closure and the balance of the critical antioxidants superoxide dismutase and glutathione in the wound bed were determined. Ischemia delayed wound closure significantly more in aged rats. Lower superoxide dismutase 2 and glutathione in non-ischemic wounds of aged rats indicate a basal deficit due to age alone. Ischemic wounds from aged rats had lower superoxide dismutase 2 protein and activity initially, coupled with decreased ratios of reduced/oxidized glutathione and lower glutathione peroxidase activity. De novo glutathione synthesis, to restore redox balance in aged ischemic wounds, was initiated as evidenced by increased glutamate cysteine ligase. Results demonstrate deficiencies in two antioxidant pathways in aged rats that become exaggerated in ischemic tissue, culminating in profoundly impaired wound healing and prolonged inflammation.
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Affiliation(s)
- Andrea N Moor
- Department of Molecular Pharmacology and Physiology, University of South Florida, 12901 Bruce B. Downs Blvd, MDC 8, Tampa, FL, 33612, USA,
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Bradley-Whitman MA, Timmons MD, Beckett TL, Murphy MP, Lynn BC, Lovell MA. Nucleic acid oxidation: an early feature of Alzheimer's disease. J Neurochem 2013; 128:294-304. [PMID: 24032632 DOI: 10.1111/jnc.12444] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/27/2013] [Accepted: 08/30/2013] [Indexed: 12/20/2022]
Abstract
Studies of oxidative damage during the progression of Alzheimer's disease (AD) suggest its central role in disease pathogenesis. To investigate levels of nucleic acid oxidation in both early and late stages of AD, levels of multiple base adducts were quantified in nuclear and mitochondrial DNA from the superior and middle temporal gyri (SMTG), inferior parietal lobule (IPL), and cerebellum (CER) of age-matched normal control subjects, subjects with mild cognitive impairment, preclinical AD, late-stage AD, and non-AD neurological disorders (diseased control; DC) using gas chromatography/mass spectrometry. Median levels of multiple DNA adducts in nuclear and mitochondrial DNA were significantly (p ≤ 0.05) elevated in the SMTG, IPL, and CER in multiple stages of AD and in DC subjects. Elevated levels of fapyguanine and fapyadenine in mitochondrial DNA suggest a hypoxic environment early in the progression of AD and in DC subjects. Overall, these data suggest that oxidative damage is an early event not only in the pathogenesis of AD but is also present in neurodegenerative diseases in general. Levels of oxidized nucleic acids in nDNA and mtDNA were found to be significantly elevated in mild cognitive impairment (MCI), preclinical Alzheimer's disease (PCAD), late-stage AD (LAD), and a pooled diseased control group (DC) of frontotemporal dementia (FTD) and dementia with Lewy bodies (DLB) subjects compared to normal control (NC) subjects. Nucleic acid oxidation peaked early in disease progression and remained elevated. The study suggests nucleic acid oxidation is a general event in neurodegeneration.
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Affiliation(s)
- Melissa A Bradley-Whitman
- Sanders-Brown Center on Aging and Alzheimer's Disease Center, University of Kentucky, Lexington, Kentucky, USA
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9
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Radak Z, Ihasz F, Koltai E, Goto S, Taylor AW, Boldogh I. The redox-associated adaptive response of brain to physical exercise. Free Radic Res 2013; 48:84-92. [PMID: 23870001 DOI: 10.3109/10715762.2013.826352] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Reactive oxygen species (ROS) are continuously generated during metabolism. ROS are involved in redox signaling, but in significant concentrations they can greatly elevate oxidative damage leading to neurodegeneration. Because of the enhanced sensitivity of brain to ROS, it is especially important to maintain a normal redox state in brain and spinal cord cell types. The complex effects of exercise benefit brain function, including functional enhancement as well as its preventive and therapeutic roles. Exercise can induce neurogenesis via neurotrophic factors, increase capillarization, decrease oxidative damage, and enhance repair of oxidative damage. Exercise is also effective in attenuating age-associated loss in brain function, which suggests that physical activity-related complex metabolic and redox changes are important for a healthy neural system.
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Affiliation(s)
- Z Radak
- Faculty of Physical Education and Sport Sciences, Institute of Sport Science, Semmelweis University , Budapest , Hungary
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10
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Hajas G, Bacsi A, Aguilera-Aguirre L, Hegde ML, Tapas KH, Sur S, Radak Z, Ba X, Boldogh I. 8-Oxoguanine DNA glycosylase-1 links DNA repair to cellular signaling via the activation of the small GTPase Rac1. Free Radic Biol Med 2013; 61:384-94. [PMID: 23612479 PMCID: PMC3795866 DOI: 10.1016/j.freeradbiomed.2013.04.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Revised: 02/24/2013] [Accepted: 04/09/2013] [Indexed: 12/20/2022]
Abstract
8-Oxo-7,8-dihydroguanine (8-oxoG) is one of the most abundant DNA base lesions induced by reactive oxygen species (ROS). Accumulation of 8-oxoG in the mammalian genome is considered a marker of oxidative stress, to be causally linked to inflammation, and is thought to contribute to aging processes and various aging-related diseases. Unexpectedly, mice that lack 8-oxoguanine DNA glycosylase-1 (OGG1) activity and accumulate 8-oxoG in their genome have a normal phenotype and longevity; in fact, they show increased resistance to both inflammation and oxidative stress. OGG1 excises and generates free 8-oxoG base during DNA base-excision repair (BER) processes. In the present study, we report that in the presence of the 8-oxoG base, OGG1 physically interacts with guanine nucleotide-free and GDP-bound Rac1 protein. This interaction results in rapid GDP→GTP, but not GTP→GDP, exchange in vitro. Importantly, a rise in the intracellular 8-oxoG base levels increases the proportion of GTP-bound Rac1. In turn Rac1-GTP mediates an increase in ROS levels via nuclear membrane-associated NADPH oxidase type 4. These results show a novel mechanism by which OGG1 in complex with 8-oxoG is linked to redox signaling and cellular responses.
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Affiliation(s)
- Gyorgy Hajas
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Attila Bacsi
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Leopoldo Aguilera-Aguirre
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Muralidhar L Hegde
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - K Hazra Tapas
- Department of Internal Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA; Department of Biochemistry & Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Sanjiv Sur
- Department of Internal Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Zsolt Radak
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Xueqing Ba
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| | - Istvan Boldogh
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA; Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA.
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11
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Santos RX, Correia SC, Zhu X, Smith MA, Moreira PI, Castellani RJ, Nunomura A, Perry G. Mitochondrial DNA oxidative damage and repair in aging and Alzheimer's disease. Antioxid Redox Signal 2013; 18:2444-57. [PMID: 23216311 PMCID: PMC3671662 DOI: 10.1089/ars.2012.5039] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SIGNIFICANCE Mitochondria are fundamental to the life and proper functioning of cells. These organelles play a key role in energy production, in maintaining homeostatic levels of second messengers (e.g., reactive oxygen species and calcium), and in the coordination of apoptotic cell death. The role of mitochondria in aging and in pathophysiological processes is constantly being unraveled, and their involvement in neurodegenerative processes, such as Alzheimer's disease (AD), is very well known. RECENT ADVANCES A considerable amount of evidence points to oxidative damage to mitochondrial DNA (mtDNA) as a determinant event that occurs during aging, which may cause or potentiate mitochondrial dysfunction favoring neurodegenerative events. Concomitantly to reactive oxygen species production, an inefficient mitochondrial base excision repair (BER) machinery has also been pointed to favor the accumulation of oxidized bases in mtDNA during aging and AD progression. CRITICAL ISSUES The accumulation of oxidized mtDNA bases during aging increases the risk of sporadic AD, an event that is much less relevant in the familial forms of the disease. This aspect is critical for the interpretation of data arising from tissue of AD patients and animal models of AD, as the major part of animal models rely on mutations in genes associated with familial forms of the disease. FUTURE DIRECTIONS Further investigation is important to unveil the role of mtDNA and BER in aging brain and AD in order to design more effective preventive and therapeutic strategies.
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Affiliation(s)
- Renato X Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
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12
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Radak Z, Zhao Z, Koltai E, Ohno H, Atalay M. Oxygen consumption and usage during physical exercise: the balance between oxidative stress and ROS-dependent adaptive signaling. Antioxid Redox Signal 2013; 18:1208-46. [PMID: 22978553 PMCID: PMC3579386 DOI: 10.1089/ars.2011.4498] [Citation(s) in RCA: 395] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The complexity of human DNA has been affected by aerobic metabolism, including endurance exercise and oxygen toxicity. Aerobic endurance exercise could play an important role in the evolution of Homo sapiens, and oxygen was not important just for survival, but it was crucial to redox-mediated adaptation. The metabolic challenge during physical exercise results in an elevated generation of reactive oxygen species (ROS) that are important modulators of muscle contraction, antioxidant protection, and oxidative damage repair, which at moderate levels generate physiological responses. Several factors of mitochondrial biogenesis, such as peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), mitogen-activated protein kinase, and SIRT1, are modulated by exercise-associated changes in the redox milieu. PGC-1α activation could result in decreased oxidative challenge, either by upregulation of antioxidant enzymes and/or by an increased number of mitochondria that allows lower levels of respiratory activity for the same degree of ATP generation. Endogenous thiol antioxidants glutathione and thioredoxin are modulated with high oxygen consumption and ROS generation during physical exercise, controlling cellular function through redox-sensitive signaling and protein-protein interactions. Endurance exercise-related angiogenesis, up to a significant degree, is regulated by ROS-mediated activation of hypoxia-inducible factor 1α. Moreover, the exercise-associated ROS production could be important to DNA methylation and post-translation modifications of histone residues, which create heritable adaptive conditions based on epigenetic features of chromosomes. Accumulating data indicate that exercise with moderate intensity has systemic and complex health-promoting effects, which undoubtedly involve regulation of redox homeostasis and signaling.
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Affiliation(s)
- Zsolt Radak
- Faculty of Physical Education and Sport Science, Institute of Sport Science, Semmelweis University, Budapest, Hungary.
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13
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Abstract
The average lifespan of humans is increasing, and with it the percentage of people entering the 65 and older age group is growing rapidly and will continue to do so in the next 20 years. Within this age group, cardiovascular disease will remain the leading cause of death, and the cost associated with treatment will continue to increase. Aging is an inevitable part of life and unfortunately poses the largest risk factor for cardiovascular disease. Although numerous studies in the cardiovascular field have considered both young and aged humans, there are still many unanswered questions as to how the genetic pathways that regulate aging in model organisms influence cardiovascular aging. Likewise, in the molecular biology of aging field, few studies fully assess the role of these aging pathways in cardiovascular health. Fortunately, this gap is beginning to close, and these two fields are merging together. We provide an overview of some of the key genes involved in regulating lifespan and health span, including sirtuins, AMP-activated protein kinase, mammalian target of rapamycin, and insulin-like growth factor 1 and their roles regulating cardiovascular health. We then discuss a series of review articles that will appear in succession and provide a more comprehensive analysis of studies carried out linking genes of aging and cardiovascular health, and perspectives of future directions of these two intimately linked fields.
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Affiliation(s)
- Brian J North
- Glenn Laboratories for the Biological Mechanisms of Aging, Department of Genetics, Harvard Medical School, Boston, MA, USA.
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14
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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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15
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Santos RX, Correia SC, Zhu X, Lee HG, Petersen RB, Nunomura A, Smith MA, Perry G, Moreira PI. Nuclear and mitochondrial DNA oxidation in Alzheimer's disease. Free Radic Res 2012; 46:565-76. [DOI: 10.3109/10715762.2011.648188] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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16
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Koltai E, Zhao Z, Lacza Z, Cselenyak A, Vacz G, Nyakas C, Boldogh I, Ichinoseki-Sekine N, Radak Z. Combined exercise and insulin-like growth factor-1 supplementation induces neurogenesis in old rats, but do not attenuate age-associated DNA damage. Rejuvenation Res 2011; 14:585-96. [PMID: 21867412 DOI: 10.1089/rej.2011.1178] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
We have investigated the effects of 2 weeks of insulin-like growth factor-1 (IGF-1) supplementation (5 μg/kg per day) and 6 weeks of exercise training (60% of the maximal oxygen consumption [VO₂ max]) on neurogenesis, DNA damage/repair, and sirtuin content in the hippocampus of young (3 months old) and old (26 months old) rats. Exercise improved the spatial memory of the old group, but IGF-1 supplementation eliminated this effect. An age-associated decrease in neurogenesis was attenuated by exercise and IGF-1 treatment. Aging increased the levels of 8-oxo-7,8-dihydroguanine (8-oxoG) and the protein Ku70, indicating the role of DNA damage in age-related neuropathology. Acetylation of 8-oxoguanine DNA glycosylase (OGG1) was detected in vivo, and this decreased with aging. However, in young animals, exercise and IGF-1 treatment increased acetylated (ac) OGG1 levels. Sirtuin 1 (SIRT1) and SIRT3, as DNA damage-associated lysine deacetylases, were measured, and SIRT1 decreased with aging, resulting in a large increase in acetylated lysine residues in the hippocampus. On the other hand, SIRT3 increased with aging. Exercise-induced neurogenesis might not be a causative factor of increased spatial memory, because IGF-1 plus exercise can induce neurogenesis in the hippocampus of older rats. Data revealed that the age-associated increase in 8-oxoG levels is due to decreased acetylation of OGG1. Age-associated decreases in SIRT1 and the associated increase in lysine acetylation, in the hippocampus, could have significant impact on function and thus, could suggest a therapeutic target.
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Affiliation(s)
- Erika Koltai
- Semmelweis University , Research Institute of Sport Science, Budapest, Hungary
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17
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Radak Z, Bori Z, Koltai E, Fatouros IG, Jamurtas AZ, Douroudos II, Terzis G, Nikolaidis MG, Chatzinikolaou A, Sovatzidis A, Kumagai S, Naito H, Boldogh I. Age-dependent changes in 8-oxoguanine-DNA glycosylase activity are modulated by adaptive responses to physical exercise in human skeletal muscle. Free Radic Biol Med 2011; 51:417-23. [PMID: 21569841 PMCID: PMC3775599 DOI: 10.1016/j.freeradbiomed.2011.04.018] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 04/06/2011] [Accepted: 04/11/2011] [Indexed: 01/25/2023]
Abstract
8-Oxo-7,8-dihydroguanine (8-oxoG) accumulates in the genome over time and is believed to contribute to the development of aging characteristics of skeletal muscle and various aging-related diseases. Here, we show a significantly increased level of intrahelical 8-oxoG and 8-oxoguanine-DNA glycosylase (OGG1) expression in aged human skeletal muscle compared to that of young individuals. In response to exercise, the 8-oxoG level was lastingly elevated in sedentary young and old subjects, but returned rapidly to preexercise levels in the DNA of physically active individuals independent of age. 8-OxoG levels in DNA were inversely correlated with the abundance of acetylated OGG1 (Ac-OGG1), but not with total OGG1, apurinic/apyrimidinic endonuclease 1 (APE1), or Ac-APE1. The actual Ac-OGG1 level was linked to exercise-induced oxidative stress, as shown by changes in lipid peroxide levels and expression of Cu,Zn-SOD, Mn-SOD, and SIRT3, as well as the balance between acetyltransferase p300/CBP and deacetylase SIRT1, but not SIRT6 expression. Together these data suggest that that acetylated form of OGG1, and not OGG1 itself, correlates inversely with the 8-oxoG level in the DNA of human skeletal muscle, and the Ac-OGG1 level is dependent on adaptive cellular responses to physical activity, but is age independent.
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Affiliation(s)
- Zsolt Radak
- Research Institute of Sport Science, Semmelweis University, Budapest H-1123, Hungary.
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Prunier C, Masson-Genteuil G, Ugolin N, Sarrazy F, Sauvaigo S. Aging and photo-aging DNA repair phenotype of skin cells-evidence toward an effect of chronic sun-exposure. Mutat Res 2011; 736:48-55. [PMID: 21669211 DOI: 10.1016/j.mrfmmm.2011.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 04/18/2011] [Accepted: 05/07/2011] [Indexed: 12/15/2022]
Abstract
Several studies have demonstrated the deleterious effect of aging on the capacity of cells to repair their DNA. However, current existing assays aimed at measuring DNA repair address only a specific repair step dedicated to the correction of a specific DNA lesion type. Consequently they provide no information regarding the repair pathways that handle other types of lesions. In addition to aging, consequences of photo-exposure on these repair processes remain elusive. In this study we evaluated the consequence of aging and of chronic and/or acute photo-exposure on DNA repair in human skin fibroblasts using a multiplexed approach, which provided detailed information on several repair pathways at the same time. The resulting data were analyzed with adapted statistics/bioinformatics tools. We showed that, irrespective of the repair pathway considered, excision/synthesis was less efficient in non-exposed cells from elderly compared to cells from young adults and that photo-exposure disrupted this very clear pattern. Moreover, it was evidenced that chronic sun-exposure induced changes in DNA repair properties. Finally, the identification of a specific signature at the level of the NER pathway in cells repeatedly exposed to sun revealed a cumulative effect of UVB exposure and chronic sun irradiation. The uses of bioinformatics tools in this study was essential to fully take advantage of the large sum of data obtained with our multiplexed DNA repair assay and unravel the effects of environmental exposure on DNA repair pathways.
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Affiliation(s)
- Chloé Prunier
- Laboratoire Lésions des Acides Nucléiques, Grenoble Cedex 9, France
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19
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Arif M, Senapati P, Shandilya J, Kundu TK. Protein lysine acetylation in cellular function and its role in cancer manifestation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:702-16. [PMID: 20965294 DOI: 10.1016/j.bbagrm.2010.10.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 10/08/2010] [Accepted: 10/12/2010] [Indexed: 01/05/2023]
Abstract
Lysine acetylation appears to be crucial for diverse biological phenomena, including all the DNA-templated processes, metabolism, cytoskeleton dynamics, cell signaling, and circadian rhythm. A growing number of cellular proteins have now been identified to be acetylated and constitute the complex cellular acetylome. Cross-talk among protein acetylation together with other post-translational modifications fine-tune the cellular functions of different protein machineries. Dysfunction of acetylation process is often associated with several diseases, especially cancer. This review focuses on the recent advances in the role of protein lysine acetylation in diverse cellular functions and its implications in cancer manifestation.
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Affiliation(s)
- Mohammed Arif
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur (P.O.), Bangalore-560 064, Karnataka, India
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20
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Radak Z, Boldogh I. 8-Oxo-7,8-dihydroguanine: links to gene expression, aging, and defense against oxidative stress. Free Radic Biol Med 2010; 49:587-96. [PMID: 20483371 PMCID: PMC2943936 DOI: 10.1016/j.freeradbiomed.2010.05.008] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 05/06/2010] [Accepted: 05/10/2010] [Indexed: 02/07/2023]
Abstract
The one-electron oxidation product of guanine, 8-oxo-7,8-dihydroguanine (8-oxoG), is an abundant lesion in genomic, mitochondrial, and telomeric DNA and RNA. It is considered to be a marker of oxidative stress that preferentially accumulates at the 5' end of guanine strings in the DNA helix, in guanine quadruplexes, and in RNA molecules. 8-OxoG has a lower oxidation potential compared to guanine; thus it is susceptible to oxidation/reduction and, along with its redox products, is traditionally considered to be a major mutagenic DNA base lesion. It does not change the architecture of the DNA double helix and it is specifically recognized and excised by 8-oxoguanine DNA glycosylase (OGG1) during the DNA base excision repair pathway. OGG1 null animals accumulate excess levels of 8-oxoG in their genome, yet they do not have shorter life span nor do they exhibit severe pathological symptoms including tumor formation. In fact they are increasingly resistant to inflammation. Here we address the rarely considered significance of 8-oxoG, such as its optimal levels in DNA and RNA under a given condition, essentiality for normal cellular physiology, evolutionary role, and ability to soften the effects of oxidative stress in DNA, and the harmful consequences of its repair, as well as its importance in transcriptional initiation and chromatin relaxation.
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Affiliation(s)
- Zsolt Radak
- Research Institute of Sport Science, Faculty of Physical Education and Sport Science, Semmelweis University, Budapest, Hungary.
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21
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Szczesny B, Tann AW, Mitra S. Age- and tissue-specific changes in mitochondrial and nuclear DNA base excision repair activity in mice: Susceptibility of skeletal muscles to oxidative injury. Mech Ageing Dev 2010; 131:330-7. [PMID: 20363243 DOI: 10.1016/j.mad.2010.03.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 03/17/2010] [Accepted: 03/24/2010] [Indexed: 12/25/2022]
Abstract
In this study, we investigated age- and tissue-dependent changes in the DNA base excision repair (BER) of oxidative lesions in mitochondrial and nuclear extracts by measuring single-nucleotide (SN)- and long-patch (LP)-BER activities in five tissues isolated from 4-, 10- and 20-month-old mice. Age-dependent SN-BER and LP-BER activity was increased in the mitochondria of liver, kidney and heart, but generally decreased in skeletal muscles. In contrast, no significant changes in repair activity were observed in nuclear extracts of the same tissues, except for quadriceps, where the SN-BER activity was higher in the old animals. Moreover, the BER activities in both the nucleus and the mitochondria were significantly lower in skeletal muscles compared to liver or kidney of the same mice. The protein level of three antioxidant enzymes, Mn and Cu/Zn superoxide dismutases (SOD) and catalase, was also significantly lower in skeletal muscle compared to liver or kidney. In addition, we found higher levels of protein carbonylation in the mitochondria of skeletal muscle relative to other tissues. Thus, it appears likely that mouse skeletal muscle is highly susceptible to oxidative stress due to deficiency in both repair of oxidative DNA damage and antioxidant enzymes, contributing to age-dependent muscle loss.
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Affiliation(s)
- Bartosz Szczesny
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1079, USA.
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22
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Kisby GE, Kohama SG, Olivas A, Churchwell M, Doerge D, Spangler E, de Cabo R, Ingram DK, Imhof B, Bao G, Kow YW. Effect of caloric restriction on base-excision repair (BER) in the aging rat brain. Exp Gerontol 2009; 45:208-16. [PMID: 20005284 DOI: 10.1016/j.exger.2009.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Revised: 11/21/2009] [Accepted: 12/04/2009] [Indexed: 10/20/2022]
Abstract
Apyrimidinic/apurinic endonuclease (APE) is a key protein involved in the base-excision DNA repair (BER) pathway of oxidative DNA lesions. Using a novel oligonucleotide substrate, we demonstrate that APE activity in the frontal/parietal cortex (F/PCTX), cerebellum, brainstem, midbrain and hypothalamus declined with age in rats on an ad libitum (AL) diet. In contrast, APE activity for these brain regions was approximately 1.5-3 times higher in young, caloric restricted (CR) rats. Despite continuous CR treatment in all animals since six weeks of age, APE activity in the CR group started to decline by middle-age and continued into old age. However, CR maintained APE activity at a level that was significantly higher than that in AL rats across age and in the brain regions examined. Because Western analysis of APE, DNA polymerase beta and DNA ligase III levels in the F/PCTX of both CR and AL rats remained unchanged with age, this suggests that the increased APE activity in CR rats is the result of differential post-translational modification of APE.
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Affiliation(s)
- Glen E Kisby
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239, USA.
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23
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Transcriptional mutagenesis induced by 8-oxoguanine in mammalian cells. PLoS Genet 2009; 5:e1000577. [PMID: 19629170 PMCID: PMC2708909 DOI: 10.1371/journal.pgen.1000577] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Accepted: 06/25/2009] [Indexed: 11/19/2022] Open
Abstract
Most of the somatic cells of adult metazoans, including mammals, do not undergo continuous cycles of replication. Instead, they are quiescent and devote most of their metabolic activity to gene expression. The mutagenic consequences of exposure to DNA–damaging agents are well documented, but less is known about the impact of DNA lesions on transcription. To investigate this impact, we developed a luciferase-based expression system. This system consists of two types of construct composed of a DNA template containing an 8-oxoguanine, paired either with a thymine or a cytosine, placed at defined positions along the transcribed strand of the reporter gene. Analyses of luciferase gene expression from the two types of construct showed that efficient but error-prone transcriptional bypass of 8-oxoguanine occurred in vivo, and that this lesion was not repaired by the transcription-coupled repair machinery in mammalian cells. The analysis of luciferase activity expressed from 8OG:T-containing constructs indicated that the magnitude of erroneous transcription events involving 8-oxoguanine depended on the sequence contexts surrounding the lesion. Additionally, sequencing of the transcript population expressed from these constructs showed that RNA polymerase II mostly inserted an adenine opposite to 8-oxoguanine. Analysis of luciferase expression from 8OG:C-containing constructs showed that the generated aberrant mRNAs led to the production of mutant proteins with the potential to induce a long-term phenotypical change. These findings reveal that erroneous transcription over DNA lesions may induce phenotypical changes with the potential to alter the fate of non-replicating cells. The DNA molecule is used as a template for duplication, to transmit genetic information to the progeny of a given cell, but also as a template for the transcription machinery. This machinery converts genetic information from the DNA form to the RNA form used for protein synthesis. Chemical alterations of the DNA molecule caused by endogenous or environmental stresses are responsible for the generation of mutations. Indeed, these lesions can induce replication errors when DNA is duplicated during cell division. These mutations have been shown to be responsible for many genetic diseases and other sporadic diseases, such as cancer. However, less is known about their effects on transcription. We report here that a specific DNA lesion may lead to erroneous transcription events, ultimately leading to the production of aberrant proteins. The magnitude of these errors seems to depend largely on the DNA sequences surrounding the lesion and the capacity of the cell to repair this lesion. We also show that the production of aberrant protein from the erroneous transcription products may affect the phenotype of the cells concerned. Lesion-induced transcription errors may also play a role in the development of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases.
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24
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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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25
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Radak Z, Atalay M, Jakus J, Boldogh I, Davies K, Goto S. Exercise improves import of 8-oxoguanine DNA glycosylase into the mitochondrial matrix of skeletal muscle and enhances the relative activity. Free Radic Biol Med 2009; 46:238-43. [PMID: 18992806 PMCID: PMC3032603 DOI: 10.1016/j.freeradbiomed.2008.10.022] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 08/31/2008] [Accepted: 10/01/2008] [Indexed: 12/16/2022]
Abstract
Exercise has been shown to modify the level/activity of the DNA damage repair enzyme 8-oxoguanine-DNA glycosylase (OGG1) in skeletal muscle. We have studied the impact of regular physical training (8 weeks of swimming) and detraining (8 weeks of rest after an 8-week training session) on the activity of OGG1 in the nucleus and mitochondria as well as its targeting to the mitochondrial matrix in skeletal muscle. Neither exercise training nor detraining altered the overall levels of reactive species; however, mitochondrial levels of carbonylated proteins were decreased in the trained group as assessed by electron spin resonance and biochemical approaches. Importantly, nuclear OGG1 activity was increased by daily exercise training, whereas detraining reversed the up-regulating effect of training. Interestingly, training decreased the outer-membrane-associated mitochondrial OGG1 levels, whereas detraining reversed this effect. These results suggest that exercise training improves OGG1 import into the mitochondrial matrix, thereby increasing OGG1-mediated repair of oxidized guanine bases. Taken together, our data suggest that physical inactivity could impair the mitochondrial targeting of OGG1; however, exercise training increases OGG1 levels/activity in the nucleus and specific activity of OGG1 in mitochondrial compartments, thereby augmenting the repair of oxidized nuclear and mitochondrial DNA bases.
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Affiliation(s)
- Zsolt Radak
- Institute of Sport Science, Faculty of Physical Education and Sport Science, Semmelweis University, H-1123 Budapest, Hungary.
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26
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Regulatory role of human AP-endonuclease (APE1/Ref-1) in YB-1-mediated activation of the multidrug resistance gene MDR1. Mol Cell Biol 2008; 28:7066-80. [PMID: 18809583 DOI: 10.1128/mcb.00244-08] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human AP-endonuclease (APE1/Ref-1), a central enzyme involved in the repair of oxidative base damage and DNA strand breaks, has a second activity as a transcriptional regulator that binds to several trans-acting factors. APE1 overexpression is often observed in tumor cells and confers resistance to various anticancer drugs; its downregulation sensitizes tumor cells to such agents. Because the involvement of APE1 in repairing the DNA damage induced by many of these drugs is unlikely, drug resistance may be linked to APE1's transcriptional regulatory function. Here, we show that APE1, preferably in the acetylated form, stably interacts with Y-box-binding protein 1 (YB-1) and enhances its binding to the Y-box element, leading to the activation of the multidrug resistance gene MDR1. The enhanced MDR1 level due to the ectopic expression of wild-type APE1 but not of its nonacetylable mutant underscores the importance of APE1's acetylation in its coactivator function. APE1 downregulation sensitizes MDR1-overexpressing tumor cells to cisplatin or doxorubicin, showing APE1's critical role in YB-1-mediated gene expression and, thus, drug resistance in tumor cells. A systematic increase in both APE1 and MDR1 expression was observed in non-small-cell lung cancer tissue samples. Thus, our study has established the novel role of the acetylation-mediated transcriptional regulatory function of APE1, making it a potential target for the drug sensitization of tumor cells.
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27
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Moreira PI, Nunomura A, Nakamura M, Takeda A, Shenk JC, Aliev G, Smith MA, Perry G. Nucleic acid oxidation in Alzheimer disease. Free Radic Biol Med 2008; 44:1493-505. [PMID: 18258207 DOI: 10.1016/j.freeradbiomed.2008.01.002] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 12/07/2007] [Accepted: 01/08/2008] [Indexed: 01/12/2023]
Abstract
Increasing evidence suggests that oxidative stress is intimately associated with Alzheimer disease pathophysiology. Nucleic acids (nuclear DNA, mitochondrial DNA, and RNA) are one of the several cellular macromolecules damaged by reactive oxygen species, particularly the hydroxyl radical. Because neurons are irreplaceable and survive as long as the organism does, they need elaborate defense mechanisms to ensure their longevity. In Alzheimer disease, however, an accumulation of nucleic acid oxidation is observed, indicating an increased level of oxidative stress and/or a decreased capacity to repair the nucleic acid damage. In this review, we present data supporting the notion that mitochondrial and metal abnormalities are key sources of oxidative stress in Alzheimer disease. Furthermore, we outline the mechanisms of nucleic acid oxidation and repair. Finally, evidence showing the occurrence of nucleic acid oxidation in Alzheimer disease will be discussed.
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Affiliation(s)
- Paula I Moreira
- Center for Neuroscience and Cell Biology, Institute of Physiology-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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28
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Fantini D, Vascotto C, Deganuto M, Bivi N, Gustincich S, Marcon G, Quadrifoglio F, Damante G, Bhakat KK, Mitra S, Tell G. APE1/Ref-1 regulates PTEN expression mediated by Egr-1. Free Radic Res 2008; 42:20-9. [PMID: 18324520 DOI: 10.1080/10715760701765616] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
APE1/Ref-1, the mammalian ortholog of E. coli Xth, and a multifunctional protein possessing both DNA repair and transcriptional regulatory activities, has dual role in controlling cellular response to oxidative stress. It is rate-limiting in repair of oxidative DNA damage including strand breaks and also has co-transcriptional activity by modulating genes expression directly regulated by Egr-1 and p53 transcription factors. PTEN, a phosphoinositide phosphatase, acts as an 'off' switch in the PI-3 kinase/Akt signalling pathway and regulates cell growth and survival. It is shown here that transient alteration in the APE1 level in HeLa cells modulates PTEN expression and that acetylatable APE1 is required for the activation of the PTEN gene. Acetylation of APE1 enhances its binding to distinct trans-acting complexes involved in activation or repression. The acetylated protein is deacetylated in vivo by histone deacetylases. It was found that exposure of HeLa cells to H(2)O(2) and to histone deacetylase inhibitors increases acetylation of APE1 and induction of PTEN. The absence of such induction in APE1-downregulated HeLa cells confirmed APE1's role in regulating inducible PTEN expression. That APE1-dependent PTEN expression is mediated by Egr-1 was supported by experiments with cells ectopically expressing Egr-1. Thus, the data open new perspectives in the comprehension of the many functions exerted by APE1 in controlling cell response to oxidative stress.
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Affiliation(s)
- Damiano Fantini
- Department of Biomedical Sciences and Technologies, University of Udine, Udine, Italy
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29
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Druzhyna NM, Wilson GL, LeDoux SP. Mitochondrial DNA repair in aging and disease. Mech Ageing Dev 2008; 129:383-90. [PMID: 18417187 DOI: 10.1016/j.mad.2008.03.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 02/29/2008] [Accepted: 03/05/2008] [Indexed: 11/16/2022]
Abstract
Mitochondria are organelles which, according to the endosymbiosis theory, evolved from purpurbacteria approximately 1.5 billion years ago. One of the unique features of mitochondria is that they have their own genome. Mitochondria replicate and transcribe their DNA semiautonomously. Like nuclear DNA, mitochondrial DNA (mtDNA) is constantly exposed to DNA damaging agents. Regarding the repair of mtDNA, the prevailing concept for many years was that mtDNA molecules suffering an excess of damage would simply be degraded to be replaced by newly generated successors copied from undamaged genomes. However, evidence now clearly shows that mitochondria contain the machinery to repair the damage to their genomes caused by certain endogenous or exogenous damaging agents. The link between mtDNA damage and repair to aging, neurodegeneration, and carcinogenesis-associated processes is the subject of this review.
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Affiliation(s)
- Nadiya M Druzhyna
- Department of Cell Biology and Neuroscience, University of South Alabama, 307 University Boulevard, Mobile, AL 36688, USA
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30
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Akbari M, Krokan HE. Cytotoxicity and mutagenicity of endogenous DNA base lesions as potential cause of human aging. Mech Ageing Dev 2008; 129:353-65. [PMID: 18355895 DOI: 10.1016/j.mad.2008.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 01/25/2008] [Accepted: 01/28/2008] [Indexed: 11/26/2022]
Abstract
Endogenous factors constitute a substantial source of damage to the genomic DNA. The type of damage includes a number of different base lesions and single- and double-strand breaks. Unrepaired DNA damage can give rise to mutations and may cause cell death. A number of studies have demonstrated an association between aging and the accumulation of DNA damage. This may be attributed to reduced DNA repair with age, although this is apparently not a general feature for all types of damage and repair mechanisms. Therefore, detailed studies that improve our knowledge of DNA repair systems as well as mutagenic and toxic effects of DNA lesions will help us to gain a better insight into the mechanisms of aging. The aim of this review is to provide a brief description of cytotoxic and mutagenic endogenous DNA lesions that are mainly repaired by base excision repair and single-strand break repair pathways and to discuss the potential role of DNA lesions and DNA repair dysfunction in the onset of human aging.
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Affiliation(s)
- Mansour Akbari
- Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
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31
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Abstract
DNA is a precious molecule. It encodes vital information about cellular content and function. There are only two copies of each chromosome in the cell, and once the sequence is lost no replacement is possible. The irreplaceable nature of the DNA sets it apart from other cellular molecules, and makes it a critical target for age-related deterioration. To prevent DNA damage cells have evolved elaborate DNA repair machinery. Paradoxically, DNA repair can itself be subject to age-related changes and deterioration. In this review we will discuss the changes in efficiency of mismatch repair (MMR), base excision repair (BER), nucleotide excision repair (NER) and double-strand break (DSB) repair systems during aging, and potential changes in DSB repair pathway usage that occur with age. Mutations in DNA repair genes and premature aging phenotypes they cause have been reviewed extensively elsewhere, therefore the focus of this review is on the comparison of DNA repair mechanisms in young versus old.
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Affiliation(s)
- Vera Gorbunova
- Department of Biology, University of Rochester, Rochester, NY 14627, USA.
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32
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Deganuto M, Pittis MG, Pines A, Dominissini S, Kelley MR, Garcia R, Quadrifoglio F, Bembi B, Tell G. Altered intracellular redox status in Gaucher disease fibroblasts and impairment of adaptive response against oxidative stress. J Cell Physiol 2007; 212:223-35. [PMID: 17443679 DOI: 10.1002/jcp.21023] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Gaucher disease (GD) is a lysosomal storage disorder, due to glucosylceramide (GlcCer) accumulation in several body tissues, which causes cellular failure by yet unidentified mechanisms. Several evidence indicates that GD pathogenesis is associated to an impairment in intracellular redox state. In fibroblast primary cultures, reactive oxygen species (ROS) levels and protein carbonyl content resulted significantly increased in GD patients compared to healthy donors, suggesting that GD cells, facing a condition of chronic oxidative stress, have evolved an adaptive response to survive. The ROS rise is probably due to NAD(P)H oxidase activity, being inhibited by the treatment with diphenylene iodonium chloride. Interestingly, GD cells are more sensitive to H(2)O(2) induced cell death, suggesting a dysregulation in the adaptive response to oxidative stress in which APE1/Ref-1 plays a central role. We found that the cytoplasmic amounts of APE1/Ref-1 protein were significantly higher in GD fibroblasts with respect to controls, and that GD cells failed to upregulate its expression upon H(2)O(2) treatment. Both ROS and APE1/Ref-1 increases are due to GlcCer accumulation, being prevented by treatment of GD fibroblasts with Cerezyme and induced in healthy fibroblasts treated with conduritol-beta-epoxide. These data, suggesting that GD cells display an impairment in the cellular redox state and in the adaptive cellular response to oxidative stress, may open new perspectives in the comprehension of GD pathogenesis.
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Affiliation(s)
- Marta Deganuto
- Department of Biomedical Sciences and Technologies, University of Udine, Udine, Italy
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Nakamoto H, Kaneko T, Tahara S, Hayashi E, Naito H, Radak Z, Goto S. Regular exercise reduces 8-oxodG in the nuclear and mitochondrial DNA and modulates the DNA repair activity in the liver of old rats. Exp Gerontol 2007; 42:287-95. [PMID: 17204389 DOI: 10.1016/j.exger.2006.11.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 11/08/2006] [Accepted: 11/14/2006] [Indexed: 01/09/2023]
Abstract
Exercise is often said to increase the generation of reactive oxygen species that are potentially harmful. On the other hand, regular exercise has various health benefits even late in life. The specific aim of this study was to explore effects of regular exercise on oxidative status of DNA in aged animals. We report that 2 months of regular treadmill running of aged rats (21 month old) significantly reduced 8-oxodG content to the level of young adult animals (11 month old) in both nuclear and mitochondrial DNA of the liver. The mitochondrial DNA showed 10-fold higher content of the oxidative lesion than the nuclear DNA. The levels in old animals were 2- and 1.5-fold higher than that in young adults for the nucleus and mitochondria, respectively. The activity of the repair enzyme OGG1 was upregulated significantly in the nucleus but not in mitochondria by the exercise. To our knowledge, this is the first report demonstrating that regular exercise can reduce significantly oxidative damage to both the nuclear and mitochondrial DNA. We suggest that the apparent beneficial outcomes in reducing the DNA damage by regular exercise can be interpreted in terms of hormetic effect by moderate oxidative stress and potential adaptation to stronger stresses.
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Affiliation(s)
- Hideko Nakamoto
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
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Radak Z, Kumagai S, Nakamoto H, Goto S. 8-Oxoguanosine and uracil repair of nuclear and mitochondrial DNA in red and white skeletal muscle of exercise-trained old rats. J Appl Physiol (1985) 2007; 102:1696-701. [PMID: 17204574 DOI: 10.1152/japplphysiol.01051.2006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxoguanine DNA glycosylase (OGG1) and uracil DNA glycosylase (UDG) are two of the most important repair enzymes that are involved in the base excision repair processes to eliminate oxidative damage from mammalian DNA, which accumulates with aging. Red and white skeletal muscle fibers have very different antioxidant enzyme activities and resistance to oxidative stress. In this paper, we demonstrate that the activity of OGG1 is significantly higher in the red type of skeletal muscle compared with white fibers from old rats. Exercise training resulted in increased OGG1 activity in the nuclei of red fibers and decreased activity in nuclei of white fibers and in the mitochondria of both red and white fibers. The activities of UDG were similar in both red and white muscle fibers. Exercise training appears to increase the activity of UDG in the nuclei and mitochondria. However, exercise training affects the activity of OGG1 in nuclei and mitochondria differently, suggesting different regulation of the enzymes. In contrast, UDG showed similar activities in nuclei and mitochondrial extracts of exercise-trained animals. These data provide evidence for differential regulation of UDG and OGG1 in maintaining fidelity of DNA in oxidatively stressed cells.
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Affiliation(s)
- Zsolt Radak
- Institute of Sport Science, Faculty of Physical Education and Sport Science, Semmelweis University, Budapest, Hungary.
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Kriete A, Sokhansanj BA, Coppock DL, West GB. Systems approaches to the networks of aging. Ageing Res Rev 2006; 5:434-48. [PMID: 16904954 DOI: 10.1016/j.arr.2006.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 05/09/2006] [Accepted: 06/02/2006] [Indexed: 12/26/2022]
Abstract
The aging of an organism is the result of complex changes in structure and function of molecules, cells, tissues, and whole body systems. To increase our understanding of how aging works, we have to analyze and integrate quantitative evidence from multiple levels of biological organization. Here, we define a broader conceptual framework for a quantitative, computational systems biology approach to aging. Initially, we consider fractal supply networks that give rise to scaling laws relating body mass, metabolism and lifespan. This approach provides a top-down view of constrained cellular processes. Concomitantly, multi-omics data generation build such a framework from the bottom-up, using modeling strategies to identify key pathways and their physiological capacity. Multiscale spatio-temporal representations finally connect molecular processes with structural organization. As aging manifests on a systems level, it emerges as a highly networked process regulated through feedback loops between levels of biological organization.
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Affiliation(s)
- Andres Kriete
- School of Biomedical Engineering, Drexel University, Science and Health System, Chestnut Street 3401, Philadelphia, PA 19104, USA.
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Van Houten B, Woshner V, Santos JH. Role of mitochondrial DNA in toxic responses to oxidative stress. DNA Repair (Amst) 2006; 5:145-52. [PMID: 15878696 DOI: 10.1016/j.dnarep.2005.03.002] [Citation(s) in RCA: 309] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Indexed: 12/17/2022]
Abstract
Mitochondria are at the crossroads of several crucial cellular activities including: adenosine triphosphate (ATP) generation via oxidative phosphorylation; the biosynthesis of heme, pyrimidines and steroids; calcium and iron homeostasis and programmed cell death (apoptosis). Mitochondria also produce considerable quantities of superoxide and hydrogen peroxide (H2O2) that in conjunction with its large iron stores can lead to a witch's brew of reactive intermediates capable of damaging macromolecules. Mitochondrial DNA (mtDNA) represents a critical target for such oxidative damage. Once damaged, mtDNA can amplify oxidative stress by decreased expression of critical proteins important for electron transport leading to a vicious cycle of reactive oxygen species (ROS) and organellar dysregulation that eventually trigger apoptosis. Oxidative stress is associated with many human disorders including: cancer, cardiovascular disease, diabetes mellitus, liver disease and neurodegenerative disease. This article reviews the evidence that oxidative damage to mtDNA can culminate in cell death and thus represents an important target for therapeutic intervention in a number of human diseases.
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Affiliation(s)
- Bennett Van Houten
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, 111 Alexander Drive, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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Graziewicz MA, Longley MJ, Copeland WC. DNA polymerase gamma in mitochondrial DNA replication and repair. Chem Rev 2006; 106:383-405. [PMID: 16464011 DOI: 10.1021/cr040463d] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Maria A Graziewicz
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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López-Diazguerrero NE, Luna-López A, Gutiérrez-Ruiz MC, Zentella A, Königsberg M. Susceptibility of DNA to oxidative stressors in young and aging mice. Life Sci 2006; 77:2840-54. [PMID: 15979101 DOI: 10.1016/j.lfs.2005.05.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 02/24/2005] [Accepted: 05/11/2005] [Indexed: 01/06/2023]
Abstract
The changes that accompany aging may be a result of oxidative damage to DNA that accumulates as a result of aging and age-related illnesses. Furthermore, a higher susceptibility is thought to be more common among elderly than young individuals. In the present study, we examined the severity of DNA damage caused by carbon tetrachloride (CCl4) and H2O2 in cells from young (2 month old) and older (14 month old) mice using both in vivo and in vitro exposures. CCl(4) is known to generate radical oxidative species (ROS) throughout its biotransformation in the liver. Therefore, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxdGuo) was quantified in liver DNA obtained from young and older mice treated with CCl4. In addition, DNA single-strand breaks were measured by the Comet assay in primary lung fibroblasts cultured from young and older mice and treated in vitro with H2O2. Intracellular ROS production and mitochondrial enzyme activity were determined in parallel. 8-oxodGuo levels were significantly higher in older mouse liver DNA than younger, and increased significantly with CCl4 treatment. When the basal DNA damage was subtracted, the net damage was almost equal for both. In addition, untreated cells cultured from older mice had significantly greater levels of strand breaks than cells derived from young mice. H2O2 increased the level of damage in both cell cultures. Our findings indicate that the DNA damage observed in older animals probably results from the accumulation of endogenous damage with age, perhaps due to insufficient repair, which enhances the injury caused by exposure to the toxic agents.
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Affiliation(s)
- Norma E López-Diazguerrero
- Departamento de Ciencias de la Salud, División de Ciencias Biológicas y de la Salud, UAM-Iztapalapa, A.P. 55-535, México, D.F. 09340, México
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Szczesny B, Mitra S. Effect of aging on intracellular distribution of abasic (AP) endonuclease 1 in the mouse liver. Mech Ageing Dev 2006; 126:1071-8. [PMID: 15951004 DOI: 10.1016/j.mad.2005.04.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2004] [Revised: 03/01/2005] [Accepted: 04/11/2005] [Indexed: 11/26/2022]
Abstract
The abasic (AP) endonuclease (APE1) plays a central role in the base excision repair (BER) pathway for repairing oxidatively damaged bases and abasic sites in mammalian genomes. We have investigated age-dependent changes in APE activity, contributed primarily by APE1, in total extracts as well as in nuclear, mitochondrial, and cytoplasmic compartments of mouse hepatocytes. The APE1 protein and mRNA levels did not differ significantly between the livers of 4-mo (young), 10-mo (middle-aged), and 20-mo (old) mice, and corresponds with similar APE activity. However, we observed a 2-fold increase in specific activity of APE1 in the nucleus, a 2-fold decrease in the cytoplasm, and a 6-fold increase in the mitochondrial matrix of hepatocytes of the old relative to the young animals. Surprisingly, in the middle-age animals we observed 30% increase in APE activity in the nucleus but 6-fold in the mitochondrial matrix. These results indicate age-dependent accumulation of APE1 in the nucleus and mitochondria. Such redistribution occurred early in the mitochondria during the aging process and preferential accumulation of APE in the nucleus was more gradual which may reflect distinct levels of oxidative stress in these organelles.
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Affiliation(s)
- Bartosz Szczesny
- University of Texas Medical Branch, Sealy Center for Molecular Science, Department of Human Biological Chemistry and Genetics, Galveston, TX 77555, USA
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Neema M, Navarro-Quiroga I, Chechlacz M, Gilliams-Francis K, Liu J, Lamonica K, Lin SL, Naegele JR. DNA damage and nonhomologous end joining in excitotoxicity: neuroprotective role of DNA-PKcs in kainic acid-induced seizures. Hippocampus 2006; 15:1057-71. [PMID: 16216017 DOI: 10.1002/hipo.20123] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
DNA repair plays a critical, but imprecisely defined role in excitotoxic injury and neuronal survival throughout adulthood. We utilized an excitotoxic injury model to compare the location and phenotype of degenerating neurons in mice (strain 129-C57BL) deficient in the catalytic subunit of the DNA-dependent protein kinase (DNA-PKcs), an enzyme required for nonhomologous end joining (NHEJ). Brains from untreated adult heterozygous and DNA-PKcs null mice displayed comparable cytoarchitecture and undetectable levels of cell death. By day 1, and extending through 4 days following kainic acid-induced seizures, brains from DNA-PKcs null mice showed widespread neurodegeneration that encompassed the entire hippocampal CA1-CA3 pyramidal cell layer, entorhinal cortex, and lateral septum, with relative sparing of the dentate gyrus granule cell layer and hilus, as judged by toluidine blue, Fluoro-Jade B, and terminal dUTP nick end labeling staining. In contrast, seizure-related neurodegeneration in heterozygous littermates was limited to the CA3 region of the hippocampus. NeuN and calbindin staining revealed a selective decrease in the number and density of NeuN-positive neurons in the pyramidal layers of degenerating regions in both heterozygous and DNA-PKcs null mice. To elucidate the mechanisms leading to cell death, we examined an involvement of the p53 pathway, known to be induced by DNA damage. Addition of pifithrin-alpha, a p53 inhibitor, or expression of a dominant-negative p53 rescued neurons from kainate-induced excitotoxic cell death in primary cortical cultures derived from wildtype, DNA-PKcs heterozygous, or DNA-PKcs null neonatal mice. Moreover, pifithrin-alpha prevented kainate-induced loss of mitochondrial membrane potential, dendrite degeneration, and cell death. Results suggest that NHEJ plays a neuroprotective role in excitotoxicity, within the perforant, Schaffer collateral, hippocampal-septal, and temperoammonic pathways, in part by repairing DNA damage that would otherwise result in activation of a p53-dependent apoptotic cascade.
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Affiliation(s)
- Mohit Neema
- Department of Biology and Program in Neuroscience and Behavior, Wesleyan University, Middletown, CT 06459-0170, USA
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Berneburg M, Kamenisch Y, Krutmann J. Repair of mitochondrial DNA in aging and carcinogenesis. Photochem Photobiol Sci 2005; 5:190-8. [PMID: 16465305 DOI: 10.1039/b507380d] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mitochondria are responsible for the generation of energy in the form of adenosine triphosphate. These organelles contain their own genetic material, mitochondrial (mt) DNA. This mtDNA has been hypothesized to play a role in the processes of aging and carcinogenesis. Initial reports have shown that there is no repair of cyclobutylpyrimidine dimers (CPD). More recent reports indicate however, that the mitochondrion contains several defence mechanisms against endogenous or exogenous damaging agents such as ultraviolet radiation or oxidative damage. The role of these defence mechanisms in the removal of mitochondrial DNA damage and the link to aging and carcinogenesis-associated processes are discussed in this review.
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Affiliation(s)
- Mark Berneburg
- Molecular Oncology and Aging, Department of Dermatology, Eberhard Karls University, Liebermeisterstrasse 25, D-72076 Tübingen, Germany.
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Kang MK, Kim RH, Shin KH, Zhong W, Faull KF, Park NH. Senescence-associated decline in the intranuclear accumulation of hOGG1-alpha and impaired 8-oxo-dG repair activity in senescing normal human oral keratinocytes in vivo. Exp Cell Res 2005; 310:186-95. [PMID: 16122734 DOI: 10.1016/j.yexcr.2005.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 07/12/2005] [Accepted: 07/21/2005] [Indexed: 11/30/2022]
Abstract
We determined the mitochondrial membrane status, presence of reactive oxygen species (ROS), and oxidative DNA adduct formation in normal human oral keratinocytes (NHOK) during senescence. The senescent cells showed accumulation of intracellular ROS and 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG), a major oxidative DNA adduct. Exposure of cells to H2O2 induced 8-oxo-dG accumulation in cellular DNA, which was rapidly removed in replicating NHOK. However, the 8-oxo-dG removal activity was almost completely abolished in the senescing culture. Both replicating and senescing NHOK expressed readily detectable 8-oxo-dG DNA glycosylase (hOGG1), the enzyme responsible for glycosidic cleavage of 8-oxo-dG. After exposure to H2O2, however, the intranuclear level of the hOGG1-alpha isoform was decreased in senescing but not in replicating NHOK. These results indicated that senescing NHOK accumulated oxidative DNA lesions in part due to increased level of endogenous ROS and impaired intranuclear translocation of hOGG1 enzyme upon exposure to oxidative stress.
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Affiliation(s)
- Mo K Kang
- UCLA School of Dentistry, CHS 43-009, 10833 Le Conte Avenue, Los Angeles, CA 90095-1668, USA.
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Bacsi A, Stanton GJ, Hughes TK, Kruze M, Boldogh I. Colostrinin-Driven Neurite Outgrowth Requires p53 Activation in PC12 Cells. Cell Mol Neurobiol 2005; 25:1123-39. [PMID: 16392041 DOI: 10.1007/s10571-005-8222-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Accepted: 08/29/2005] [Indexed: 10/25/2022]
Abstract
1. Colostrinin (CLN) induces maturation and differentiation of murine thymocytes, promotes proliferation of peripheral blood leukocytes, induces immunomodulator cytokines, and ameliorates oxidative stress-mediated activation of c-Jun NH2-terminal kinases. 2. Here we report that upon treatment with CLN, medullary pheochromocytoma (PC12) cells ceased to proliferate and extend neurites. 3. The arrest of CLN-treated PC12 cells in the G1 phase of the cell cycle was due to an increase in the phosphorylation of p53 at serine(15) (p53ser15) and expression of p21WAF1. PC12 cells treated with inhibitory oligonucleotides to p53 lacked p53ser15 and p21WAF1 expression, and did not show morphological changes after CLN exposure. Transfection with inhibitory oligonucleotides to p21WAF1 had no effect on p53 activation; however, cells failed to arrest or extend neurites. An oligonucleotide inhibiting luciferase expression had no effect on CLN-mediated p53 activation, p21WAF1 expression, growth arrest, or neurite outgrowth. 4. We conclude that CLN induces delicate cassettes of signaling pathways common to cell proliferation and differentiation, and mediates activities that are similar to those of hormones and neurotrophins, leading to neurite outgrowth.
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Affiliation(s)
- Attila Bacsi
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
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