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Leong PK, Chen N, Ko KM. Mitochondrial decay in ageing: 'Qi-invigorating' schisandrin B as a hormetic agent for mitigating age-related diseases. Clin Exp Pharmacol Physiol 2012; 39:256-64. [PMID: 21895737 DOI: 10.1111/j.1440-1681.2011.05600.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. The mitochondrial free radical theory of ageing (MFRTA) proposes a primary role for mitochondrial reactive oxygen species (ROS) in the ageing process. The reductive hot spot hypothesis of mammalian ageing serves as a supplement to the MFRTA by explaining how the relatively few cells that have lost oxidative phosphorylation capacity due to mitochondrial DNA mutations can be toxic to the rest of the body and result in the development of age-related diseases. 2. Schisandrin B (SchB), which can induce both a glutathione anti-oxidant and a heat shock response via redox-sensitive signalling pathways, is a hormetic agent potentially useful for increasing the resistance of tissues to oxidative damage. The enhanced cellular/mitochondrial anti-oxidant status and heat shock response afforded by SchB can preserve the structural and functional integrity of mitochondria, suggesting a potential role for SchB in ameliorating age-related diseases. 3. Future studies will focus on investigating whether SchB can produce the hormetic response in humans.
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Affiliation(s)
- Pou K Leong
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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TANG CHUN, LIN HENG, FENG CHUNLIN, WU QIAO, ZHANG YUJUN, BIE PING. Mitochondrial DNA damage and its effect on mitochondrial function in rats with obstructive jaundice. Mol Med Rep 2012; 6:1393-8. [DOI: 10.3892/mmr.2012.1114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Accepted: 09/20/2012] [Indexed: 11/05/2022] Open
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Thioredoxin, oxidative stress, cancer and aging. LONGEVITY & HEALTHSPAN 2012; 1:4. [PMID: 24764510 PMCID: PMC3886257 DOI: 10.1186/2046-2395-1-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 06/20/2012] [Indexed: 11/30/2022]
Abstract
The Free Radical or Oxidative Stress Theory of Aging is one of the most popular theories in aging research and has been extensively studied over the past several decades. However, recent evidence using transgenic/knockout mice that overexpress or down-regulate antioxidant enzymes challenge the veracity of this theory since the animals show no increase or decrease in lifespan. These results seriously call into question the role of oxidative damage/stress in the aging process in mammals. Therefore, the theory requires significant modifications if we are to understand the relationship between aging and the regulation of oxidative stress. Our laboratory has been examining the impacts of thioredoxins (Trxs), in the cytosol and mitochondria, on aging and age-related diseases. Our data from mice that are either up-regulating or down-regulating Trx in different cellular compartments, that is, the cytosol or mitochondria, could shed some light on the role of oxidative stress and its pathophysiological effects. The results generated from our lab and others may indicate that: 1) changes in oxidative stress and the redox state in the cytosol, mitochondria or nucleus might play different roles in the aging process; 2) the role of oxidative stress and redox state could have different pathophysiological consequences in different tissues/cells, for example, mitotic vs. post-mitotic; 3) oxidative stress could have different pathophysiological impacts in young and old animals; and 4) the pathophysiological roles of oxidative stress and redox state could be controlled through changes in redox-sensitive signaling, which could have more diverse effects on pathophysiology than the accumulation of oxidative damage to various molecules. To critically test the role of oxidative stress on aging and age-related diseases, further study is required using animal models that regulate oxidative stress levels differently in each cellular compartment, each tissue/organ, and/or at different stages of life (young, middle and old) to change redox sensitive signaling pathways.
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Inafuku H, Kuniyoshi Y, Yamashiro S, Arakaki K, Nagano T, Morishima Y, Kise Y. Determination of oxidative stress and cardiac dysfunction after ischemia/reperfusion injury in isolated rat hearts. Ann Thorac Cardiovasc Surg 2012; 19:186-94. [PMID: 22971810 DOI: 10.5761/atcs.oa.12.01896] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Oxidative stress due to reactive oxygen species (ROS) is thought to play a considerable role in ischemia/reperfusion (I/R) injury that impairs cardiac function. The present study examined oxidative damage in I/R injury and investigated the correlation between oxidative stress and impaired cardiac function after I/R injury of the isolated rat heart. METHODS Hearts isolated from male Sprague-Dawley rats were mounted on a Langendorff apparatus. Hearts arrested using St. Thomas cardioplegic solution and then they were reperfused. The hearts were divided into three groups depending on the frequency (0-2) of I/R. After I/R, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), positive maximum left ventricular developing pressure (max LV dP/dt) and coronary flow (CF) were measured. Creatine kinase (CK) was measured in the coronary effluent and 8-hydroxy-2'deoxyguanosine (8OHdG), a marker of oxidative DNA damage, was measured. Adenosine triphosphate (ATP) was measured from frozen myocardial tissue after experiment. RESULTS We immunohistochemically demonstrated and quantified levels of 8-OHdG after I/R injury of the heart. The frequency of I/R injury and cardiac dysfunction significantly and negatively correlated. The ATP products were similar among the three groups. The incidence of ventricular arrhythmias was not by affected oxidative stress. CONCLUSION The frequency of I/R injury had more of an effect on 8-OHdG products and on impaired cardiac function with less myocyte damage than ischemic duration within 30 minutes of ischemia.
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Affiliation(s)
- Hitoshi Inafuku
- Department of Thoracic and Cardiovascular Surgery, University of the Ryukyus, Nishihara, Okinawa, Japan.
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Abstract
Mitochondrial DNA (mtDNA) 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 be particularly deleterious in post-mitotic cells, including neurons, and to play a critical role in the aging process and in a variety of diseases. Thus, efficient mtDNA repair is important for the maintenance of genomic integrity and a healthy life. The base excision repair (BER) mechanism was the first to be described in mitochondria, and consequently it is the best known. This chapter outlines protocols for isolating mitochondria from mammalian cells in culture and from rodent tissues including liver and brain. It also covers the isolation of synaptic mitochondria. BER takes place in four distinct steps, and protocols describing in vitro assays for measuring these enzymatic steps in lysates of isolated mitochondria are included.
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Affiliation(s)
- Ricardo Gredilla
- Department of Molecular Biology and Genetics, University of Aarhus, Aarhus, Denmark
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Lee HC, Wei YH. Mitochondria and Aging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 942:311-27. [DOI: 10.1007/978-94-007-2869-1_14] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Pérez VI, Cortez LA, Lew CM, Rodriguez M, Webb CR, Van Remmen H, Chaudhuri A, Qi W, Lee S, Bokov A, Fok W, Jones D, Richardson A, Yodoi J, Zhang Y, Tominaga K, Hubbard GB, Ikeno Y. Thioredoxin 1 overexpression extends mainly the earlier part of life span in mice. J Gerontol A Biol Sci Med Sci 2011; 66:1286-99. [PMID: 21873593 DOI: 10.1093/gerona/glr125] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We examined the effects of increased levels of thioredoxin 1 (Trx1) on resistance to oxidative stress and aging in transgenic mice overexpressing Trx1 [Tg(TRX1)(+/0)]. The Tg(TRX1)(+/0) mice showed significantly higher Trx1 protein levels in all the tissues examined compared with the wild-type littermates. Oxidative damage to proteins and levels of lipid peroxidation were significantly lower in the livers of Tg(TRX1)(+/0) mice compared with wild-type littermates. The survival study demonstrated that male Tg(TRX1)(+/0) mice significantly extended the earlier part of life span compared with wild-type littermates, but no significant life extension was observed in females. Neither male nor female Tg(TRX1)(+/0) mice showed changes in maximum life span. Our findings suggested that the increased levels of Trx1 in the Tg(TRX1)(+/0) mice were correlated to increased resistance to oxidative stress, which could be beneficial in the earlier part of life span but not the maximum life span in the C57BL/6 mice.
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Affiliation(s)
- Viviana I Pérez
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA
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Wang J, Wang Q, Watson LJ, Jones SP, Epstein PN. Cardiac overexpression of 8-oxoguanine DNA glycosylase 1 protects mitochondrial DNA and reduces cardiac fibrosis following transaortic constriction. Am J Physiol Heart Circ Physiol 2011; 301:H2073-80. [PMID: 21873502 DOI: 10.1152/ajpheart.00157.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cardiac failure is associated with increased levels of oxidized DNA, especially mitochondrial (mtDNA). It is not known if oxidized mtDNA contributes to cardiac dysfunction. To test if protection of mtDNA can reduce cardiac injury, we produced transgenic mice with cardiomyocyte-specific overexpression of the DNA repair enzyme 8-oxoguanine DNA glycosylase 1 (OGG1) isoform 2a. In one line of mice, the transgene increased OGG1 activity by 115% in mitochondria and by 28% in nuclei. OGG1 transgenic mice demonstrated significantly lower cardiac mitochondrial levels of the DNA guanine oxidation product 7,8-dihydro-8-oxoguanine (8-oxo-dG) under basal conditions, after doxorubicin administration, or after transaortic constriction (TAC), but the transgene produced no detectable reduction in nuclear 8-oxo-dG content. OGG1 mice were tested for protection from the cardiac effects of TAC 13 wk after surgery. Compared with FVB-TAC mice, hearts from OGG1-TAC mice had lower levels of β-myosin heavy chain mRNA but they did not display significant differences in the ratio of heart weight to tibia length or protection of cardiac function measured by echocardiography. The principle benefit of OGG1 overexpression was a significant decrease in TAC-induced cardiac fibrosis. This protection was indicated by reduced Sirius red staining on OGG1 cardiac sections and by significantly decreased induction of collagen 1 and 3 mRNA expression in OGG1 hearts after TAC surgery. These results provide a new model to assess the damaging cardiac effects of 8-oxo-dG formation and suggest that increased repair of 8-oxo-dG in mtDNA decreases cardiac pathology.
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Affiliation(s)
- Jianxun Wang
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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60
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Mao P, Reddy PH. Aging and amyloid beta-induced oxidative DNA damage and mitochondrial dysfunction in Alzheimer's disease: implications for early intervention and therapeutics. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1359-70. [PMID: 21871956 DOI: 10.1016/j.bbadis.2011.08.005] [Citation(s) in RCA: 215] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 08/10/2011] [Accepted: 08/10/2011] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is an age-related progressive neurodegenerative disease affecting thousands of people in the world and effective treatment is still not available. Over two decades of intense research using AD postmortem brains, transgenic mouse and cell models of amyloid precursor protein and tau revealed that amyloid beta (Aβ) and hyperphosphorylated tau are synergistically involved in triggering disease progression. Accumulating evidence also revealed that aging and amyloid beta-induced oxidative DNA damage and mitochondrial dysfunction initiate and contributes to the development and progression of the disease. The purpose of this article is to summarize the latest progress in aging and AD, with a special emphasis on the mitochondria, oxidative DNA damage including methods of its measurement. It also discusses the therapeutic approaches against oxidative DNA damage and treatment strategies in AD.
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Affiliation(s)
- Peizhong Mao
- Neurogenetics Laboratory, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA
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Pamplona R, Barja G. An evolutionary comparative scan for longevity-related oxidative stress resistance mechanisms in homeotherms. Biogerontology 2011; 12:409-35. [PMID: 21755337 DOI: 10.1007/s10522-011-9348-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 06/29/2011] [Indexed: 01/09/2023]
Abstract
Key mechanisms relating oxidative stress to longevity from an interespecies comparative approach are reviewed. Long-lived animal species show low rates of reactive oxygen species (ROS) generation and oxidative damage at their mitochondria. Comparative physiology also shows that the specific compositional pattern of tissue macromolecules (proteins, lipids and nucleic acids) in long-lived animal species gives them an intrinsically high resistance to modification that likely contributes to their superior longevity. This is obtained in the case of lipids by decreasing the degree of fatty acid unsaturation, and in the case of proteins by lowering their methionine content. These findings are also substantiated from a phylogenomic approach. Nutritional or/and pharmacological interventions focused to modify some of these molecular traits were translated with modifications in animal longevity. It is proposed that natural selection tends to decrease the mitochondrial ROS generation and to increase the molecular resistance to the oxidative damage in long-lived species.
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Affiliation(s)
- Reinald Pamplona
- Department of Experimental Medicine, University of Lleida-IRBLleida, Lleida, 25008, Spain.
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Kızıl G, Kızıl M, Çeken B, Yavuz M, Demir H. Protective Ability of Ethanol Extracts ofHypericum ScabrumL. andHypericum RetusumAucher Against the Protein Oxidation and DNA Damage. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2011. [DOI: 10.1080/10942910903491181] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Hirunuma M, Shoyama Y, Sasaki K, Sakamoto S, Taura F, Shoyama Y, Tanaka H, Morimoto S. Flavone-catalyzed apoptosis in Scutellaria baicalensis. PHYTOCHEMISTRY 2011; 72:752-760. [PMID: 21377703 DOI: 10.1016/j.phytochem.2011.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 12/03/2010] [Accepted: 02/08/2011] [Indexed: 05/30/2023]
Abstract
In response to mechanical damage, roots of Scutellaria baicalensis undergo cell death within 24h. The flavone baicalein was identified as the factor regulating apoptosis in the damaged roots of S. baicalensis. Plant apoptosis is known to be triggered by oxidative damage of DNA through oxidative bursts, whereas baicalein causes apoptosis in Scutellaria cells by a copper-dependent oxidation of nuclear DNA without inducing an oxidative burst. S. baicalensis possesses an interesting system for quickly producing this apoptosis-inducing flavone in its cells. Intact Scutellaria cells contain little baicalein but store a large amount of baicalin (baicalein 7-O-β-D-glucuronide). Stress treatment of Scutellaria cells immediately initiates hydrolysis of baicalin by endogenous β-glucuronidase, and the resulting baicalein is immediately translocated to the nucleus, leading to apoptosis. Thus, S. baicalensis possesses a unique apoptosis-inducing system that is linked with metabolism of baicalin.
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Affiliation(s)
- Motosuke Hirunuma
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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Sepici-Dincel A, Sahin D, Karasu Benli AC, Sarikaya R, Selvi M, Erkoc F, Altan N. Genotoxicity assessment of carp (Cyprinus carpioL.) fingerlings by tissue DNA damage and micronucleus test, after environmental exposure to fenitrothion. Toxicol Mech Methods 2011; 21:388-92. [DOI: 10.3109/15376516.2010.551553] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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KATO D, KOMORIYA M, NAKAMOTO K, KURITA R, HIRONO S, NIWA O. Electrochemical Determination of Oxidative Damaged DNA with High Sensitivity and Stability Using a Nanocarbon Film. ANAL SCI 2011; 27:703. [DOI: 10.2116/analsci.27.703] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Dai KATO
- National Institute of Advanced Industrial Science and Technology (AIST)
| | | | | | - Ryoji KURITA
- National Institute of Advanced Industrial Science and Technology (AIST)
| | | | - Osamu NIWA
- National Institute of Advanced Industrial Science and Technology (AIST)
- University of Tsukuba
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Fujita R, Tanaka Y, Saihara Y, Yamakita M, Ando D, Koyama K. Effect of Molecular Hydrogen Saturated Alkaline Electrolyzed Water on Disuse Muscle Atrophy in Gastrocnemius Muscle. J Physiol Anthropol 2011; 30:195-201. [DOI: 10.2114/jpa2.30.195] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Gredilla R. DNA damage and base excision repair in mitochondria and their role in aging. J Aging Res 2010; 2011:257093. [PMID: 21234332 PMCID: PMC3018712 DOI: 10.4061/2011/257093] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 12/14/2010] [Indexed: 12/28/2022] Open
Abstract
During the last decades, our knowledge about the processes involved in the aging process has exponentially increased. However, further investigation will be still required to globally understand the complexity of aging. Aging is a multifactorial phenomenon characterized by increased susceptibility to cellular loss and functional decline, where mitochondrial DNA mutations and mitochondrial DNA damage response are thought to play important roles. Due to the proximity of mitochondrial DNA to the main sites of mitochondrial-free radical generation, oxidative stress is a major source of mitochondrial DNA mutations. Mitochondrial DNA repair mechanisms, in particular the base excision repair pathway, constitute an important mechanism for maintenance of mitochondrial DNA integrity. The results reviewed here support that mitochondrial DNA damage plays an important role in aging.
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Affiliation(s)
- Ricardo Gredilla
- Department of Physiology, Faculty of Medicine, Complutense University, Plaza Ramón y Cajal s/n. 28040 Madrid, Spain
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68
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The antioxidant effects of garlic saponins protect PC12 cells from hypoxia-induced damage. Br J Nutr 2010; 105:1164-72. [PMID: 21205417 DOI: 10.1017/s0007114510004939] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hypoxia frequently occurs under several different cellular circumstances. Excess reactive oxygen species that are induced by hypoxia may result in cell injury and dysfunction. Recently, garlic has been found to possess some biological and pharmacological activities. The present study examined the effects of garlic saponins (GSP) on the survival of differentiated PC12 (dPC12) cells and the oxidative-antioxidant system. dPC12 cells were exposed to 2 % O2 in order to establish a neuronal insult model. Cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction assay and lactate dehydrogenase (LDH) release assay. The expression of selected genes (catalase (CAT), p65 and neuron-specific class III β-tubulin) was evaluated by real-time PCR and immunoblot assays. CAT activity, malondialdehyde (MDA) and 8-hydroxy-deoxyguanosine (8-OH-dG) concentrations were also determined. The data showed that hypoxia dramatically damaged dPC12 cells, while treatment with approximately 5 × 10- 2-10 ng/ml GSP improved cell viability, decreased LDH leakage and caused the cells to maintain neuronal-like characteristics in hypoxia. The production of MDA and 8-OH-dG was attenuated by GSP. CAT activity in dPC12 cells pretreated with GSP was higher than that of the hypoxic control. Moreover, GSP up-regulated CAT expression and decreased the total protein expression as well as the nuclear expression of p65 in hypoxic cells. These data indicate that GSP has antioxidant properties that can protect dPC12 cells from hypoxia-induced damage, which may be related to the up-regulation of CAT expression and activity as well as a decrease in the expression and nucleus distribution of p65 through effects on redox-sensitive signalling pathways.
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Altan N, Sepici-Dinçel A, Sahin D, Kocamanoğlu N, Kosova F, Engin A. Oxidative DNA damage: the thyroid hormone-mediated effects of insulin on liver tissue. Endocrine 2010; 38:214-20. [PMID: 20703869 DOI: 10.1007/s12020-010-9376-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 07/02/2010] [Indexed: 01/01/2023]
Abstract
Thyroid hormone affects glucose homeostasis with its actions between the skeletal muscle and liver and the altered oxidative and non-oxidative glucose metabolism. In our study three chemicals are considered biomarkers associated with oxidative stress for protein modifications were measured; 8-hydroxy-2-deoxyyguanosine (8-OHdG), a major lesion that can be generated by reactive oxygen species for DNA damage, protein carbonyl content (PCO), products of protein oxidation and advanced oxidation protein products (AOPPs) a dithyrosine containing cross-linked protein products. The purpose of the recent study was to determine the effects of insulin and T4 or their combination in diabetic, thyroidectomized, or diabetic-thyroidectomized rats and possible relations with oxidative DNA and protein damages. For this purpose, rats were assigned to eight groups: Group 1; control, Group 2; diabetes, Group 3; diabetes+insulin, Group 4; surgically thyroidectomized control, Group 5; thyroidectomized+diabetes, Group 6; thyroidectomized+diabetes+insulin, Group 7; thyroidectomized+diabetes+insulin+thyroid hormone, levothyroxin sodium, 2.5 μg/kg and Group 8; thyroidectomized+diabetes+insulin+thyroid hormone, levothyroxin sodium, 5.0 μg/kg for 5 weeks. After the genomic DNA of liver tissues was extracted, the ratio of 8-OHdG to deoxyguanosine and liver tissue protein oxidation markers was determined. The main findings of our recent study were the increased 8-OHdG levels during the diabetes, hypothyroidism, and hypothyroidism with diabetes, which can be regulated in different percentages with the treatment of 2.5 and 5.0 μg/kg doses of thyroid hormone and the altered protein carbonyl and AOPP levels of liver tissue. Consequently, it was observed that the DNA and protein damage induced by oxidative stress in diabetes could be regulated by dose-dependent thyroid hormone-mediated effects to insulin treatment.
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Affiliation(s)
- Nilgün Altan
- Department of Medical Biochemistry, Faculty of Medicine, Gazi University, Ankara, Turkey.
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Maynard S, de Souza-Pinto NC, Scheibye-Knudsen M, Bohr VA. Mitochondrial base excision repair assays. Methods 2010; 51:416-25. [PMID: 20188838 PMCID: PMC2916069 DOI: 10.1016/j.ymeth.2010.02.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 02/23/2010] [Indexed: 12/12/2022] Open
Abstract
The main source of mitochondrial DNA (mtDNA) damage is reactive oxygen species (ROS) generated during normal cellular metabolism. The main mtDNA lesions generated by ROS are base modifications, such as the ubiquitous 8-oxoguanine (8-oxoG) lesion; however, base loss and strand breaks may also occur. Many human diseases are associated with mtDNA mutations and thus maintaining mtDNA integrity is critical. All of these lesions are repaired primarily by the base excision repair (BER) pathway. It is now known that mammalian mitochondria have BER, which, similarly to nuclear BER, is catalyzed by DNA glycosylases, AP endonuclease, DNA polymerase (POLgamma in mitochondria) and DNA ligase. This article outlines procedures for measuring oxidative damage formation and BER in mitochondria, including isolation of mitochondria from tissues and cells, protocols for measuring BER enzyme activities, gene-specific repair assays, chromatographic techniques as well as current optimizations for detecting 8-oxoG lesions in cells by immunofluorescence. Throughout the assay descriptions we will include methodological considerations that may help optimize the assays in terms of resolution and repeatability.
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Affiliation(s)
- Scott Maynard
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, Baltimore, MD 21236, USA
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Hebert SL, Lanza IR, Nair KS. Mitochondrial DNA alterations and reduced mitochondrial function in aging. Mech Ageing Dev 2010; 131:451-62. [PMID: 20307565 PMCID: PMC2910809 DOI: 10.1016/j.mad.2010.03.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Revised: 03/03/2010] [Accepted: 03/14/2010] [Indexed: 12/23/2022]
Abstract
Oxidative damage to mitochondrial DNA increases with aging. This damage has the potential to affect mitochondrial DNA replication and transcription which could alter the abundance or functionality of mitochondrial proteins. This review describes mitochondrial DNA alterations and changes in mitochondrial function that occur with aging. Age-related alterations in mitochondrial DNA as a possible contributor to the reduction in mitochondrial function are discussed.
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Affiliation(s)
| | | | - K. Sreekumaran Nair
- Corresponding author: K. Sreekumaran Nair, Endocrine Research Unit, Mayo Clinic, 200 First St. SW, Joseph 5-194, Rochester, MN 55905, Telephone: 507-255-2415, Fax: 507-255-4828,
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Tudek B, Winczura A, Janik J, Siomek A, Foksinski M, Oliński R. Involvement of oxidatively damaged DNA and repair in cancer development and aging. Am J Transl Res 2010; 2:254-284. [PMID: 20589166 PMCID: PMC2892402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 05/06/2010] [Indexed: 05/29/2023]
Abstract
DNA damage and DNA repair may mediate several cellular processes, like replication and transcription, mutagenesis and apoptosis and thus may be important factors in the development and pathology of an organism, including cancer. DNA is constantly damaged by reactive oxygen species (ROS) and reactive nitrogen species (RNS) directly and also by products of lipid peroxidation (LPO), which form exocyclic adducts to DNA bases. A wide variety of oxidatively-generated DNA lesions are present in living cells. 8-oxoguanine (8-oxoGua) is one of the best known DNA lesions due to its mutagenic properties. Among LPO-derived DNA base modifications the most intensively studied are ethenoadenine and ethenocytosine, highly miscoding DNA lesions considered as markers of oxidative stress and promutagenic DNA damage. Although at present it is impossible to directly answer the question concerning involvement of oxidatively damaged DNA in cancer etiology, it is likely that oxidatively modified DNA bases may serve as a source of mutations that initiate carcinogenesis and are involved in aging (i.e. they may be causal factors responsible for these processes). To counteract the deleterious effect of oxidatively damaged DNA, all organisms have developed several DNA repair mechanisms. The efficiency of oxidatively damaged DNA repair was frequently found to be decreased in cancer patients. The present work reviews the basis for the biological significance of DNA damage, particularly effects of 8-oxoGua and ethenoadduct occurrence in DNA in the aspect of cancer development, drawing attention to the multiplicity of proteins with repair activities.
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Affiliation(s)
- Barbara Tudek
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Institute of Genetics and Biotechnology,Warsaw University, Poland.
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Lewis KN, Mele J, Hayes JD, Buffenstein R. Nrf2, a guardian of healthspan and gatekeeper of species longevity. Integr Comp Biol 2010; 50:829-43. [PMID: 21031035 DOI: 10.1093/icb/icq034] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Although aging is a ubiquitous process that prevails in all organisms, the mechanisms governing both the rate of decline in functionality and the age of onset remain elusive. A profound constitutively upregulated cytoprotective response is commonly observed in naturally long-lived species and experimental models of extensions to lifespan (e.g., genetically-altered and/or experimentally manipulated organisms), as indicated by enhanced resistance to stress and upregulated downstream components of the cytoprotective nuclear factor erythroid 2-related factor 2 (Nrf2)-signaling pathway. The transcription factor Nrf2 is constitutively expressed in all tissues, although levels may vary among organs, with the key detoxification organs (kidney and liver) exhibiting highest levels. Nrf2 may be further induced by cellular stressors including endogenous reactive-oxygen species or exogenous electrophiles. The Nrf2-signaling pathway mediates multiple avenues of cytoprotection by activating the transcription of more than 200 genes that are crucial in the metabolism of drugs and toxins, protection against oxidative stress and inflammation, as well as playing an integral role in stability of proteins and in the removal of damaged proteins via proteasomal degradation or autophagy. Nrf2 interacts with other important cell regulators such as tumor suppressor protein 53 (p53) and nuclear factor-kappa beta (NF-κB) and through their combined interactions is the guardian of healthspan, protecting against many age-related diseases including cancer and neurodegeneration. We hypothesize that this signaling pathway plays a critical role in the determination of species longevity and that this pathway may indeed be the master regulator of the aging process.
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Affiliation(s)
- Kaitlyn N Lewis
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, STCBM 2.2, San Antonio, TX 78245, USA
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75
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Abstract
Mitochondrial dysfunction is heavily implicated in the multifactorial aging process. Aging humans have increased levels of somatic mtDNA mutations that tend to undergo clonal expansion to cause mosaic respiratory chain deficiency in various tissues, such as heart, brain, skeletal muscle, and gut. Genetic mouse models have shown that somatic mtDNA mutations and cell type-specific respiratory chain dysfunction can cause a variety of phenotypes associated with aging and age-related disease. There is thus strong observational and experimental evidence to implicate somatic mtDNA mutations and mosaic respiratory chain dysfunction in the mammalian aging process. The hypothesis that somatic mtDNA mutations are generated by oxidative damage has not been conclusively proven. Emerging data instead suggest that the inherent error rate of mitochondrial DNA (mtDNA) polymerase gamma (Pol gamma) may be responsible for the majority of somatic mtDNA mutations. The roles for mtDNA damage and replication errors in aging need to be further experimentally addressed.
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76
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Hu CW, Yen CC, Huang YL, Pan CH, Lu FJ, Chao MR. Oxidatively damaged DNA induced by humic acid and arsenic in maternal and neonatal mice. CHEMOSPHERE 2010; 79:93-99. [PMID: 20079519 DOI: 10.1016/j.chemosphere.2009.12.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 05/28/2023]
Abstract
We measured the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), a useful biomarker of oxidative injury, in liver (or urine) of maternal mice and their offspring, that were treated with humic acid (HA) and arsenic (As) alone, or their combination during pregnancy. A highly sensitive and specific isotope-dilution LC-MS/MS method was used for 8-oxodGuo quantification. Total arsenic accumulated in the offspring was also measured using ICP-MS. This study demonstrated, for the first time in an animal model, that HA alone treatment led to a significant increase of 8-oxodGuo levels both in liver and urine of maternal mice. No enhanced effect was observed when HA was combined with As, compared with the As alone treatment. With regard to the associated offspring, elevated levels of 8-oxodGuo and total arsenic were observed in offspring only when mother mice were treated with As and its combination with HA, but not for the HA-treated alone. It was worthy to note that the offspring from maternal combined treatment with HA and As had a significantly lower 8-oxodGuo than those of maternal treatment with As alone. This could be explained by that part of As formed complexes with HA and these macromolecules of HA-As complexes may not readily cross the placenta to the fetus, as evidenced by the lower accumulated total As observed in the offspring livers. Overall, it seems that HA may be detrimental to the maternal mice, but in the meantime it can be beneficial to the offspring by reducing free As.
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Affiliation(s)
- Chiung-Wen Hu
- Department of Public Health, Chung Shan Medical University, Taichung 402, Taiwan
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77
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Abstract
The ability to conduct validated analyses of biomarkers is critically important in order to establish the sensitivity and selectivity of the biomarker in identifying a particular disease. The use of stable-isotope dilution (SID) methodology in combination with LC–MS/MS provides the highest possible analytical specificity for quantitative determinations. This methodology is now widely used in the discovery and validation of putative exposure and disease biomarkers. This review will describe the application of SID LC–MS methodology for the analysis of small-molecule and protein biomarkers. It will also discuss potential future directions for the use of this methodology for rigorous biomarker analysis.
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Affiliation(s)
- Eugene Ciccimaro
- Thermo Fisher Scientific, 265 Davidson Avenue, Somerset, NJ 08873–4120, USA
| | - Ian A Blair
- Centers of Excellence in Environmental Toxicology and Cancer Pharmacology, Department of Pharmacology, University of Pennsylvania School of Medicine, 421 Curie Blvd, Philadelphia, PA 19104–6160, USA
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78
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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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79
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Austad SN. Methusaleh's Zoo: how nature provides us with clues for extending human health span. J Comp Pathol 2009; 142 Suppl 1:S10-21. [PMID: 19962715 DOI: 10.1016/j.jcpa.2009.10.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 10/26/2009] [Indexed: 10/20/2022]
Abstract
As impressive as the accomplishments of modern molecular biologists have been in finding genetic alterations that lengthen life in short-lived model organisms, they pale in comparison to the remarkable diversity of lifespans produced by evolution. Some animal species are now firmly documented to live for more than four centuries and even some mammals, like the bowhead whale, appear to survive 200 years or more. Another group of species may not be as absolutely long-lived, but they are remarkably long-lived for their body size and metabolic rate. These species include a number of bats, some of which live for at least 40 years in the wild, as well as the naked mole-rat, which is the same size, but lives nearly 10 times as long as the laboratory mouse. Together these exceptionally long-lived organisms have important roles to play in our future understanding of the causal mechanisms and modulation of ageing. Bats and naked mole-rats in particular have already contributed in the following ways: (1) they have contributed to the abandonment of the rate-of-living theory and weakened enthusiasm for the oxidative stress hypothesis of ageing, (2) they have helped evaluate how the tumour-suppressing role of cellular senescence is affected by the evolution of diverse body sizes as well as diverse longevities, (3) they have shed light on the relationship between specific types of DNA repair and ageing and (4) they have yielded insight into new processes, specifically the maintenance of the proteome and hypotheses concerning how evolution shapes ageing. The continuing acceleration of progress in genome sequencing and development of more and more cross-species investigatory techniques will facilitate even more contributions of these species in the near future.
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Affiliation(s)
- S N Austad
- University of Texas Health Science Center San Antonio, Barshop Institute for Longevity and Aging Studies, Department of Cellular and Structural Biology, 15355 Lambda Drive, STCBM Rm. 3.100, San Antonio, TX 78245, USA.
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80
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Tomruk A, Guler G, Dincel AS. The Influence of 1800 MHz GSM-like Signals on Hepatic Oxidative DNA and Lipid Damage in Nonpregnant, Pregnant, and Newly born Rabbits. Cell Biochem Biophys 2009; 56:39-47. [DOI: 10.1007/s12013-009-9068-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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81
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Zhang Y, Ikeno Y, Qi W, Chaudhuri A, Li Y, Bokov A, Thorpe SR, Baynes JW, Epstein C, Richardson A, Van Remmen H. Mice deficient in both Mn superoxide dismutase and glutathione peroxidase-1 have increased oxidative damage and a greater incidence of pathology but no reduction in longevity. J Gerontol A Biol Sci Med Sci 2009; 64:1212-20. [PMID: 19776219 DOI: 10.1093/gerona/glp132] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
To test the impact of increased mitochondrial oxidative stress as a mechanism underlying aging and age-related pathologies, we generated mice with a combined deficiency in two mitochondrial-localized antioxidant enzymes, Mn superoxide dismutase (MnSOD) and glutathione peroxidase-1 (Gpx-1). We compared life span, pathology, and oxidative damage in Gpx1(-/-), Sod2(+/-)Gpx1(+/-), Sod2(+/-)Gpx1(-/-), and wild-type control mice. Oxidative damage was elevated in Sod2(+/-)Gpx1(-/-) mice, as shown by increased DNA oxidation in liver and skeletal muscle and increased protein oxidation in brain. Surprisingly, Sod2(+/-)Gpx1(-/-) mice showed no reduction in life span, despite increased levels of oxidative damage. Consistent with the important role for oxidative stress in tumorigenesis during aging, the incidence of neoplasms was significantly increased in the older Sod2(+/-)Gpx1(-/-) mice (28-30 months). Thus, these data do not support a significant role for increased oxidative stress as a result of compromised mitochondrial antioxidant defenses in modulating life span in mice and do not support the oxidative stress theory of aging.
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Affiliation(s)
- Yiqiang Zhang
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245, USA
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82
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Zarebski M, Wiernasz E, Dobrucki JW. Recruitment of heterochromatin protein 1 to DNA repair sites. Cytometry A 2009; 75:619-25. [PMID: 19479850 DOI: 10.1002/cyto.a.20734] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Heterochromatin protein 1 (HP1) was originally identified as a constitutive component of heterochromatin. However it is recognized now that it plays an important role in a number of dynamic processes in the cell nucleus, including transcriptional repression and regulation of euchromatic genes. Recent reports demonstrate that HP1 may be involved in the DNA damage response. Two seemingly contradictory phenomena have been observed-HP1 detachment from chromatin and HP1 recruitment to damaged DNA foci. Based on quantitative FRAP and FLIP studies carefully designed to minimize phototoxicity, we demonstrate that HP1 is recruited to the damaged regions in hetero- as well as euchromatin within a few minutes after damage.
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83
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Mangal D, Vudathala D, Park JH, Lee SH, Penning TM, Blair IA. Analysis of 7,8-dihydro-8-oxo-2'-deoxyguanosine in cellular DNA during oxidative stress. Chem Res Toxicol 2009; 22:788-97. [PMID: 19309085 PMCID: PMC2684441 DOI: 10.1021/tx800343c] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
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Analysis of cellular 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dGuo) as a biomarker of oxidative DNA damage has been fraught with numerous methodological problems. This is primarily due to artifactual oxidation of dGuo that occurs during DNA isolation and hydrolysis. Therefore, it has become necessary to rely on using the comet assay, which is not necessarily specific for 8-oxo-dGuo. A highly specific and sensitive method based on immunoaffinity purification and stable isotope dilution liquid chromatography (LC)-multiple reaction monitoring (MRM)/mass spectrometry (MS) that avoids artifact formation has now been developed. Cellular DNA was isolated using cold DNAzol (a proprietary product that contains guanidine thiocyanate) instead of chaotropic- or phenol-based methodology. Chelex-treated buffers were used to prevent Fenton chemistry-mediated generation of reactive oxygen species (ROS) and artifactual oxidation of DNA bases. Deferoxamine was also added to all buffers in order to complex any residual transition metal ions remaining after Chelex treatment. The LC-MRM/MS method was used to determine that the basal 8-oxo-dGuo level in DNA from human bronchoalveolar H358 cells was 2.2 ± 0.4 8-oxo-dGuo/107 dGuo (mean ± standard deviation) or 5.5 ± 1.0 8-oxo-dGuo/108 nucleotides. Similar levels were observed in human lung adenocarcinoma A549 cells, mouse hepatoma Hepa-1c1c7 cells, and human HeLa cervical epithelial adenocarcinoma cells. These values are an order of magnitude lower than is typically reported for basal 8-oxo-dGuo levels in DNA as determined by other MS- or chromatography-based assays. H358 cells were treated with increasing concentrations of potassium bromate (KBrO3) as a positive control or with the methylating agent methyl methanesulfonate (MMS) as a negative control. A linear dose−response for 8-oxo-dGuo formation (r2 = 0.962) was obtained with increasing concentrations of KBrO3 in the range of 0.05 mM to 2.50 mM. In contrast, no 8-oxo-dGuo was observed in H358 cell DNA after treatment with MMS. At low levels of oxidative DNA damage, there was an excellent correlation between a comet assay that measured DNA single strand breaks (SSBs) after treatment with human 8-oxo-guanine glycosylase-1 (hOGG1) when compared with 8-oxo-dGuo in the DNA as measured by the stable isotope dilution LC-MRM/MS method. Availability of the new LC-MRM/MS assay made it possible to show that the benzo[a]pyrene (B[a]P)-derived quinone, B[a]P-7,8-dione, could induce 8-oxo-dGuo formation in H358 cells. This most likely occurred through redox cycling between B[a]P-7,8-dione and B[a]P-7,8-catechol with concomitant generation of DNA damaging ROS. In keeping with this concept, inhibition of catechol-O-methyl transferase (COMT)-mediated detoxification of B[a]P-7,8-catechol with Ro 410961 caused increased 8-oxo-dGuo formation in the H358 cell DNA.
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Affiliation(s)
- Dipti Mangal
- Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania, 854 BRB II/III, 421 Curie Boulevard, Philadelphia, Pennsylvania 19104-6160, USA
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84
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Espinosa O, Jiménez-Almazán J, Chaves FJ, Tormos MC, Clapes S, Iradi A, Salvador A, Fandos M, Redón J, Sáez GT. Urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxo-dG), a reliable oxidative stress marker in hypertension. Free Radic Res 2009; 41:546-54. [PMID: 17454137 DOI: 10.1080/10715760601164050] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
UNLABELLED The potential use of oxidative stress products as disease markers and progression is an important aspect of biomedical research. In the present study, the quantification of urine 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) concentration has been used to express the oxidation status of hypertensive subjects. 8-oxo-dG has been simultaneously isolated and assayed in nuclear (nDNA) and mitochondrial DNA (mtDNA). In addition, oxidative stress of mononuclear cells has been estimated by means of GSH and GSSG levels and GSSG/GSH ratio in hypertensive subjects before and after antihypertensive treatment. It is shown that oxidative stress decreases significantly in hypertensive patients after treatment the effect being accompanied by reduction of their blood pressure. A significant correlation is observed comparing the yield of urine 8-oxo-dG and that isolated from mitochondria DNA. Moreover, urinary excretion of 8-oxo-dG also correlates with the GSSG/GSH ratio of cells. CONCLUSION urine 8-oxo-dG assay is a good marker for monitoring oxidative stress changes in hypertensives.
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Affiliation(s)
- Olga Espinosa
- Oxidative Pathology Unit, Department of Biochemistry and Molecular Biology, School of Medicine, University of Valencia, Valencia, Spain
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85
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Pérez VI, Bokov A, Van Remmen H, Mele J, Ran Q, Ikeno Y, Richardson A. Is the oxidative stress theory of aging dead? Biochim Biophys Acta Gen Subj 2009; 1790:1005-14. [PMID: 19524016 DOI: 10.1016/j.bbagen.2009.06.003] [Citation(s) in RCA: 428] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 05/14/2009] [Accepted: 06/04/2009] [Indexed: 01/18/2023]
Abstract
Currently, the oxidative stress (or free radical) theory of aging is the most popular explanation of how aging occurs at the molecular level. While data from studies in invertebrates (e.g., C. elegans and Drosophila) and rodents show a correlation between increased lifespan and resistance to oxidative stress (and in some cases reduced oxidative damage to macromolecules), direct evidence showing that alterations in oxidative damage/stress play a role in aging are limited to a few studies with transgenic Drosophila that overexpress antioxidant enzymes. Over the past eight years, our laboratory has conducted an exhaustive study on the effect of under- or overexpressing a large number and wide variety of genes coding for antioxidant enzymes. In this review, we present the survival data from these studies together. Because only one (the deletion of the Sod1 gene) of the 18 genetic manipulations we studied had an effect on lifespan, our data calls into serious question the hypothesis that alterations in oxidative damage/stress play a role in the longevity of mice.
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Affiliation(s)
- Viviana I Pérez
- Barshop Institute for Longevity and Aging Studies, Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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86
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Wong YT, Gruber J, Jenner AM, Ng MPE, Ruan R, Tay FEH. Elevation of oxidative-damage biomarkers during aging in F2 hybrid mice: protection by chronic oral intake of resveratrol. Free Radic Biol Med 2009; 46:799-809. [PMID: 19159678 DOI: 10.1016/j.freeradbiomed.2008.12.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 12/07/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
Abstract
Resveratrol (RSV), a naturally occurring phytoalexin that can be found in red wine, berries, and peanuts, has been shown to extend both mean and maximum life span in model organisms. RSV has also been reported to shift the physiology of middle-aged mice on a high-calorie diet toward that of mice on a standard diet. These beneficial effects of RSV have been suggested to resemble caloric restriction. Our study in F2 four-way cross-hybrid mice was the first to evaluate the effects of aging and long-term RSV treatment (14.09+/-3.4 mg/L in drinking water for 6 or 12 months) on biomarkers of oxidative damage to DNA, 8-hydroxy-2'-deoxyguanosine (8OHdG); lipid, 8-iso-prostaglandin(2 alpha) (8-iso-PGF(2 alpha)); and protein, protein carbonyl content (PCC). There was a significant age-dependent accumulation of oxidative damage to DNA, lipid, and protein as well as a clear increase in urine 8-iso-PGF(2 alpha) levels in the majority of mouse tissues. Rates of age-dependent increases in damage biomarkers varied between tissues. Chronic RSV treatment elevated total RSV plasma levels and reduced the observed age-dependent accumulation of (1) 8OHdG in liver and heart, (2) 8-iso-PGF(2 alpha) in heart and urine, and (3) PCC in liver and kidney. However, a 12-month RSV intake resulted in significant elevation of 8-iso-PGF(2 alpha) and PCC in kidney. Our studies demonstrate that RSV treatment consistently attenuated oxidative damage in tissues where age-related oxidative damage accumulation was prominent, but also suggested that chronic RSV treatment may induce nephrotoxicity.
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Affiliation(s)
- Yee Ting Wong
- Cancer and Ageing Research Group, Institute of Bioengineering and Nanotechnology, Singapore
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87
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Chao MR, Chang YZ, Wong RH, Hu CW. Time course evaluation of N-nitrosodialkylamines-induced DNA alkylation and oxidation in liver of mosquito fish. Mutat Res 2009; 660:33-39. [PMID: 19007796 DOI: 10.1016/j.mrfmmm.2008.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 10/03/2008] [Accepted: 10/08/2008] [Indexed: 05/27/2023]
Abstract
Here we simultaneously measured N7-alkylguanines and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in liver of small fish, respectively, to assess the time course of the formation and removal of alkylation and oxidative damage to DNA caused by N-nitrosodialkylamines. Mosquito fish (Gambusia affinis) were killed at various times during (4 days) and post-exposure (16 days) to N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) alone or their combination with concentrations of 10 and 50mg/l. The modified guanine adducts were sensitively and selectively quantitated by isotope-dilution LC-MS/MS methods. During exposure, N7-methylguanine (N7-MeG) and N7-ethylguanine (N7-EtG) in liver DNA increased with the duration and dose of N-nitrosodialkylamine exposure, while 8-oxodG was dose-dependently induced within 1 day. It was found that NDMA formed substantially more N7-alkylated guanines and 8-oxodG than NDEA on the basis of adducts formed per micromolar concentration, suggesting that NDMA can be more easily bioactivated than NDEA to form reactive alkylating agents with the concomitant formation of oxygen radicals. After cessation of exposure, N7-alkylguanines remained elevated for 1 day and then gradually decreased over time but still higher than the background levels, even at day 16 (half-lives of 7-8 days). However, 8-oxodG was excised quickly from liver DNA and returned to the background level within 4 days post-exposure (half-lives less than 2 days). Taken together, this study firstly demonstrated that in addition to alkylation, N-nitrosodialkylamines can concurrently cause oxidative damage to DNA in vivo.
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Affiliation(s)
- Mu-Rong Chao
- Department of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan
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88
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Abstract
OBJECTIVE Free radicals that escape scavenging by antioxidant defense damage lipids, proteins, and DNA. Damage to DNA can be repaired. Therefore, both cells' antioxidant defense and their ability to repair oxidatively damaged DNA decide its fate to survive oxidative stress. Pancreatic islets cells with poor antioxidant defense were checked for their ability to remove oxidative damage form DNA. METHODS For ex vivo DNA repair, assay-cultured pancreatic islets and liver slices were treated with 1 and 10 mM H2O2, respectively, for 30 minutes. After incubation for different time intervals, 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA of these cells was estimated using monoclonal antibody raised against 8-OHdG by competitive enzyme-linked immunosorbent assay. For in vitro DNA repair assay, oxidatively damaged pBR322 was incubated with nuclear extracts of islet and liver cells, and 8-OHdG retained in the plasmid was quantitated. RESULTS Oxidative damage induced by H2O2 was removed quickly and efficiently from DNA by liver cells compared with islet cells. The repair of oxidatively damaged plasmid DNA in vitro was also performed more efficiently (P < 0.05) by nuclear extracts from liver cells compared with islet cell. CONCLUSIONS We clearly demonstrate that in addition to their low antioxidant defense, islets are very poor in rectifying the oxidative DNA damage.
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89
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Maatouk I, Bouaïcha N, Plessis MJ, Périn F. Optimization of the32P-Postlabeling/Thin Layer Chromatography Assay (32P-TLC) for In Vitro Detection of 8-Oxo-Deoxyguanosine as a Biomarker of Oxidative DNA Damage. Toxicol Mech Methods 2008; 16:313-22. [PMID: 20021030 DOI: 10.1080/15376520600616909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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90
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Xu G, Herzig M, Rotrekl V, Walter CA. Base excision repair, aging and health span. Mech Ageing Dev 2008; 129:366-82. [PMID: 18423806 PMCID: PMC2526234 DOI: 10.1016/j.mad.2008.03.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 02/28/2008] [Accepted: 03/05/2008] [Indexed: 12/18/2022]
Abstract
DNA damage and mutagenesis are suggested to contribute to aging through their ability to mediate cellular dysfunction. The base excision repair (BER) pathway ameliorates a large number of DNA lesions that arise spontaneously. Many of these lesions are reported to increase with age. Oxidized guanine, repaired largely via base excision repair, is particularly well studied and shown to increase with age. Spontaneous mutant frequencies also increase with age which suggests that mutagenesis may contribute to aging. It is widely accepted that genetic instability contributes to age-related occurrences of cancer and potentially other age-related pathologies. BER activity decreases with age in multiple tissues. The specific BER protein that appears to limit activity varies among tissues. DNA polymerase-beta is reduced in brain from aged mice and rats while AP endonuclease is reduced in spermatogenic cells obtained from old mice. The differences in proteins that appear to limit BER activity among tissues may represent true tissue-specific differences in activity or may be due to differences in techniques, environmental conditions or other unidentified differences among the experimental approaches. Much remains to be addressed concerning the potential role of BER in aging and age-related health span.
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Affiliation(s)
- Guogang Xu
- Department of Cellular & Structural Biology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900
| | - Maryanne Herzig
- Department of Cellular & Structural Biology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900
| | - Vladimir Rotrekl
- Institute of Experimental Medicine, Department of Molecular Embryology, Masaryk University, Faculty of Medicine, Department of Biology, Kamenice 5, Building A6, 62500 Brno, Czech Republic
| | - Christi A. Walter
- Department of Cellular & Structural Biology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900
- South Texas Veteran’s Health Care System, 7400 Merton Minter Blvd, San Antonio, TX 78229
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91
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Maiti AK, Boldogh I, Spratt H, Mitra S, Hazra TK. Mutator phenotype of mammalian cells due to deficiency of NEIL1 DNA glycosylase, an oxidized base-specific repair enzyme. DNA Repair (Amst) 2008; 7:1213-20. [PMID: 18495559 DOI: 10.1016/j.dnarep.2008.03.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 03/26/2008] [Accepted: 03/28/2008] [Indexed: 10/22/2022]
Abstract
The recently characterized NEIL1 and NEIL2 are distinct from the previously characterized mammalian DNA glycosylases (OGG1 and NTH1) involved in repair of oxidized bases because of the NEILs' preference for excising base lesions from single-stranded DNA present in bubble and fork structures. OGG1 and NTH1 are active only with duplex DNA. This raises the possibility that NEILs function in the repair of base lesions during DNA replication and/or transcription. S-phase-specific activation of only NEIL1 suggests its preferential involvement in repair during DNA replication. Here we show that antisense oligonucleotides specific for human or Chinese hamster NEIL1 decreased in vivo NEIL1 levels by 70-80%, concomitant with increased oxidative damage in the genome. Moreover, NEIL1 downregulation enhanced spontaneous mutation in the Hprt locus by about 3-fold in both Chinese hamster V79 and human bronchial A549 cell lines. The mutant frequency was further enhanced (7-8-fold) under oxidative stress. The majority of both spontaneous and induced mutations occurred at A.T base pairs, indicating that oxidized A and/or T are NEIL1's preferred in vivo substrates. NEIL1 thus plays a distinct and important role in repairing endogenous and induced mutagenic oxidized bases, and hence in maintaining the functional integrity of mammalian genomes.
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Affiliation(s)
- Amit K Maiti
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
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92
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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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93
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Han ES, Muller FL, Pérez VI, Qi W, Liang H, Xi L, Fu C, Doyle E, Hickey M, Cornell J, Epstein CJ, Roberts LJ, Van Remmen H, Richardson A. The in vivo gene expression signature of oxidative stress. Physiol Genomics 2008; 34:112-26. [PMID: 18445702 DOI: 10.1152/physiolgenomics.00239.2007] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
How higher organisms respond to elevated oxidative stress in vivo is poorly understood. Therefore, we measured oxidative stress parameters and gene expression alterations (Affymetrix arrays) in the liver caused by elevated reactive oxygen species induced in vivo by diquat or by genetic ablation of the major antioxidant enzymes CuZn-superoxide dismutase (Sod1) and glutathione peroxidase-1 (Gpx1). Diquat (50 mg/kg) treatment resulted in a significant increase in oxidative damage within 3-6 h in wild-type mice without any lethality. In contrast, treatment of Sod1(-/-) or Gpx1(-/-) mice with a similar concentration of diquat resulted in a significant increase in oxidative damage within an hour of treatment and was lethal, i.e., these mice are extremely sensitive to the oxidative stress generated by diquat. The expression response to elevated oxidative stress in vivo does not involve an upregulation of classic antioxidant genes, although long-term oxidative stress in Sod1(-/-) mice leads to a significant upregulation of thiol antioxidants (e.g., Mt1, Srxn1, Gclc, Txnrd1), which appears to be mediated by the redox-sensitive transcription factor Nrf2. The main finding of our study is that the common response to elevated oxidative stress with diquat treatment in wild-type, Gpx1(-/-), and Sod1(-/-) mice and in untreated Sod1(-/-) mice is an upregulation of p53 target genes (p21, Gdf15, Plk3, Atf3, Trp53inp1, Ddit4, Gadd45a, Btg2, Ndrg1). A retrospective comparison with previous studies shows that induction of these p53 target genes is a conserved expression response to oxidative stress, in vivo and in vitro, in different species and different cells/organs.
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Affiliation(s)
- Eun-Soo Han
- Department of Biological Science, University of Tulsa, Tulsa, Oklahoma, USA
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94
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Abstract
Among this year's highlights in vertebrate aging research, we find a study in which, contrary to the oxidative stress hypothesis of aging, reduced expression of a major cellular antioxidant, glutathione peroxidase 4, led to a small increase in mouse lifespan. By contrast, a large comparative proteomic analysis discovered a remarkably robust and previous unsuspected inverse association between species lifespan and relative frequency of cysteine residues in mitochondrially encoded respiratory chain proteins only, which the authors attribute to cysteine's ease of oxidation. Another study evaluated more cleanly than any previous work the hypothesis that blood glucose concentration is a key mediator of aging, and concluded that it wasn't. Several new mouse longevity mutants were also reported this year, some (PAPP-A, IRS-1, and IRS-2 knockouts) supporting previous work on the importance of insulin/insulin-like growth factor-1 signaling and aging. However, there were inconsistencies between laboratories in some of the results, which merit further investigation. Also, somewhat inconsistent with these findings, over-expression of insulin-like growth factor-1 in heart only lengthened life. From a completely new direction, type 5 adenylyl cyclase knockout mice were observed to live more than 30% longer than controls. Finally, a new program for evaluating potential pharmaceutical interventions in aging and longevity made its appearance, and is notable at this point chiefly for the excellence of its experimental design. A similar program for the disinterested evaluation of reported longevity mutations in mice would be a service to the community of vertebrate aging researchers.
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Affiliation(s)
- Steven Austad
- University of Texas Health Science Center, Barshop Center for Longevity and Aging Studies, San Antonio, TX 78245, USA.
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95
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Heydari AR, Unnikrishnan A, Lucente LV, Richardson A. Caloric restriction and genomic stability. Nucleic Acids Res 2007; 35:7485-96. [PMID: 17942423 PMCID: PMC2190719 DOI: 10.1093/nar/gkm860] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Caloric restriction (CR) reduces the incidence and progression of spontaneous and induced tumors in laboratory rodents while increasing mean and maximum life spans. It has been suggested that CR extends longevity and reduces age-related pathologies by reducing the levels of DNA damage and mutations that accumulate with age. This hypothesis is attractive because the integrity of the genome is essential to a cell/organism and because it is supported by observations that both cancer and immunological defects, which increase significantly with age and are delayed by CR, are associated with changes in DNA damage and/or DNA repair. Over the last three decades, numerous laboratories have examined the effects of CR on the integrity of the genome and the ability of cells to repair DNA. The majority of studies performed indicate that the age-related increase in oxidative damage to DNA is significantly reduced by CR. Early studies suggest that CR reduces DNA damage by enhancing DNA repair. With the advent of genomic technology and our increased understanding of specific repair pathways, CR has been shown to have a significant effect on major DNA repair pathways, such as NER, BER and double-strand break repair.
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Affiliation(s)
- Ahmad R Heydari
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
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96
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Bacsi A, Chodaczek G, Hazra TK, Konkel D, Boldogh I. Increased ROS generation in subsets of OGG1 knockout fibroblast cells. Mech Ageing Dev 2007; 128:637-49. [PMID: 18006041 DOI: 10.1016/j.mad.2007.09.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 09/17/2007] [Accepted: 09/22/2007] [Indexed: 11/17/2022]
Abstract
Oxoguanine DNA glycosylase (OGG1) is a major base excision repair protein responsible for excision of the mutagenic 8-oxoguanosine (8-oxoG) lesions from the genome. Despite OGG1's importance, the moderate phenotype of Ogg1-null (Ogg1(-/-)) mice is not well understood. This study addresses a mechanism by which Ogg1(-/-) cells limit accumulation of 8-oxoG in their genome. Our data reveal that a subset of Ogg1(-/-) cells shows higher ROS levels ((H)ROS cells), while approximately 85% of Ogg1(-/-) cells exhibit physiological levels of ROS ((L)ROS cells). Ogg1(-/-) cells were sorted based on their DCF fluorescence intensity to obtain (L)ROS and (H)ROS cell cultures. (L)ROS cultures proliferated at a rate comparable to Ogg1(+/+) and gradually accumulated cells exhibiting increased ROS and 8-oxoG levels. (L)ROS cells show a 2.8-fold increase in 8-oxoG level vs. (H)ROS cells (7-27-fold). Mitochondria of (H)ROS cells released more H(2)O(2) than (L)ROS and Ogg1(+/+) cells and were eliminated by apoptotic-like processes. These findings suggest that in the absence of OGG1, a surveillance system is activated that removes cells with extreme 8-oxoG levels from Ogg1(-/-) cultures. Whether similar mechanisms exists in tissues of Ogg1(-/-) mice is the focus of future investigations.
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Affiliation(s)
- Attila Bacsi
- Department of Microbiology and Immunology, University of Texas Medical Branch ,Galveston, TX 77555, USA
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97
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Frisard MI, Broussard A, Davies SS, Roberts LJ, Rood J, de Jonge L, Fang X, Jazwinski SM, Deutsch WA, Ravussin E. Aging, resting metabolic rate, and oxidative damage: results from the Louisiana Healthy Aging Study. J Gerontol A Biol Sci Med Sci 2007; 62:752-9. [PMID: 17634323 PMCID: PMC2692620 DOI: 10.1093/gerona/62.7.752] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The aging process occurs at variable rates both among and within species and may be related to the variability in oxygen consumption and free radical production impacting oxidative stress. The current study was designed to test whether nonagenarians have a relatively low metabolic rate and whether it is associated with low levels of oxidative stress relative to age. METHODS Resting metabolic rate (RMR) and markers of oxidative stress to lipids, proteins, and DNA were measured in three groups of individuals aged 20-34 (n=47), 60-74 (n=49), and>or=90 years (n=74). RESULTS RMR, adjusted for fat-free mass, fat mass, and sex, was lower in both older groups when compared to the young group (p<or=.0001). There were no significant differences in urinary isoprostanes, serum protein carbonyls, or DNA fragmentation between groups, and RMR was not related to any markers of oxidative stress. CONCLUSIONS This study confirms an age-related decline in RMR independent of changes in body composition but surprisingly did not show an accumulation of oxidative damage with increasing age. Our data challenge the theory that RMR is a significant determinant of oxidative stress and therefore contributes to the aging process.
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Affiliation(s)
| | | | | | | | - Jennifer Rood
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | | | - Xiaobing Fang
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | | | | | - Eric Ravussin
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
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98
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Negishi T, Kawai K, Arakawa R, Higashi S, Nakamura T, Watanabe M, Kasai H, Fujikawa K. Increased Levels of 8-Hydroxy-2′-Deoxyguanosine in Drosophila Larval DNA after Irradiation with 364-nm Laser Light but not with X-rays. Photochem Photobiol 2007; 83:658-63. [PMID: 17576376 DOI: 10.1562/2006-05-30-ra-905] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exposure to UVA light causes damage to cellular components such as DNA and membrane lipids. We showed previously that UVA irradiation can induce mutations in Drosophila larvae and that the major lesions responsible for mutations were not thymidine dimers when wavelengths tested became longer. The use of a longer wavelength with UVA laser apparatus (364 nm) has made it possible to test the effects of this powerful light in biological organisms. In the present study, we irradiated third instar larvae of the urate-null Drosophila mutant strain y v ma-l, which is sensitive to oxidative stress, and compared the effects of 364 nm light irradiation with the effects of X-rays. To assay viability, some of the larvae were kept at 25 degrees C until they eclosed in order to obtain a measure of viability. The remaining larvae were used to measure the amount of 8-hydroxydeoxyguanosine (8-OHdG), an indicator of oxidative DNA damage. The amount of 8-OHdG increased and viability decreased in response to increased UV dose in both the y v ma-l and wild-type strains. With irradiation of 600 kJ m(-2), 8-OHdG/10(6)dG was 7.2 +/- 3.2 and 6.2 +/- 2.0 in y v ma-l and wild-type strains, respectively, whereas the respective levels were 2.2 +/- 0.6 and 2.3 +/- 0.8 without irradiation. Our results indicated that irradiation with a 364-nm laser light caused significant oxidative damage in Drosophila larval DNA; however, induction of the damage was not prohibited by urate. To the best of our knowledge, this is the first report of a study in whole animals that shows increased levels of 8-OHdG in response to 364-nm UVA. X-ray ionizing radiation is also thought to generate reactive oxygen species in irradiated cells. We found that the amount of 8-OHdG in DNA following X-ray radiation remained unchanged in both strains, though survival rates were affected. X-ray-generated oxidative damage in Drosophila cells was followed by cell death but not DNA base oxidation, and the damage was suppressed by urate. The overall results suggest significant differences in the major in vivo oxidative damage caused by 364-nm light and X-rays.
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Affiliation(s)
- Tomoe Negishi
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima, Okayama, Japan.
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99
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Greene KF, Budzinski EE, Iijima H, Dawidzik JB, DeFedericis HC, Patrzyc HB, Evans MS, Bailey DT, Freund HG, Box HC. Assessment of DNA damage at the dimer level: measurement of the formamide lesion. Radiat Res 2007; 167:146-51. [PMID: 17390722 DOI: 10.1667/rr0693.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
UVC-radiation-induced DNA damage was measured in mouse fibroblast cells using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in conjunction with isotopically labeled internal standards. The thymine glycol and formamide lesions were assayed in the form of modified dinucleoside monophosphates. The 8-oxo-7,8-dihydroguanine lesion was measured as the modified nucleoside. DNA damage in cells treated with tirapazamine was also measured. Tirapazamine is a chemotherapeutic agent that acts via a free radical mechanism. The two agents, UVC radiation and tirapazamine, produce markedly different profiles of DNA damage, reflecting their respective mechanisms of action. Both agents produce significant amounts of thymine glycol and formamide damage, but only the former produced a measurable amount of the 8-oxo-7,8-dihydroguanine lesion. The merits of measuring DNA damage at the dimer level are discussed.
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Affiliation(s)
- Kellee F Greene
- Roswell Park Cancer Institute, Cellular Stress Biology, Buffalo, New York 14263, USA
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100
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Abstract
This chapter describes the technologies used in our respective laboratories to study the incidence and repair of lesions induced in specific DNA sequences by ultraviolet light, chemical carcinogens, and products of cellular metabolism. The Southern blot method is suitable for analysis of damage and repair in the individual DNA strands of specific restriction fragments up to 25,000 nucleotides in length, whereas the ligation-mediated polymerase chain reaction approach permits analysis of shorter sequences at the nucleotide level. Both methods have unique advantages and limitations for particular applications.
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Affiliation(s)
- Graciela Spivak
- Department of Biological Sciences, Stanford University, California, USA
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