scholarly journals Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ken Shinmura

The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S416-S416
Author(s):  
Farook Jahoor ◽  
George E Taffet ◽  
Rajagopal V Sekhar

Abstract The free-radical theory of aging suggests that age-related functional decline is mediated by increases in free-radical induced oxidative-stress. Cells normally depend on antioxidants for protection against oxidative-stress. Glutathione is the most abundant endogenous intracellular antioxidant protein composed of 3 amino-acids, cysteine, glycine and glutamic-acid, and is known to be deficient in older-humans. We investigated Glutathione kinetics in older humans using a stable-isotope tracer-based approach, and found that compared to younger humans, older-humans had severe Glutathione deficiency as a result of decreased synthesis caused by limited availability of glycine and cysteine, and associated with elevated oxidative-stress. Orally supplementing glycine and cysteine (provided as N-acetylcysteine) at doses of 1.33mmol/kg/d and 0.81mmol/kg/d respectively for 2-weeks corrected their intracellular deficiency, normalized Glutathione synthesis rates and lowered oxidative-stress to levels in younger controls. These results suggest that short-term supplementation of GlyNAC at these doses can successfully correct intracellular Glutathione deficiency in older-humans.


Folia Medica ◽  
2013 ◽  
Vol 55 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Diana G. Ivanova ◽  
Tatyana M. Yankova

Abstract This overview is an attempt to throw a fresh look at the popular free radical theory of aging (referred to also as oxidative stress theory) which holds that the progressive decline in physiological functions is a result of accumulation of diverse deleterious changes caused by reactive oxygen species (ROS). We discuss the role of mitochondria as a major source of ROS in the cell and how these link accumulation of oxidative damage to the age-related changes in physiologic functions. The free radical theory of aging is analysed here from two different views of aging - one (the pessimistic view) that regards aging as the inevitable result of life activity the consequences of which are accumulation of errors in the genome and damage of the biomolecules, and the other (the optimistic view) which considers that it is the changes in mitochondrial pathways of apoptosis with age that cause the functional tissue changes and aging. We also discuss the possibility of delaying the aging process by appropriate diet or drug therapy, which includes also calorie restriction as a mechanism of modifying the generation of free radicals and body metabolism and thus extending lifespan as a result.


Author(s):  
Fasna K. A. ◽  
Geetha N. ◽  
Jean Maliekkal

Background: Ageing is characterized by a gradual decline in body functions and decreased ability to maintain homeostasis. The free radical theory of ageing proposed by Harman D states that ageing is a result of cumulative damage incurred by free radical reactions. Free radicals are highly reactive molecular species with unpaired electrons; generated in the body by several physiological processes. Prime target to free radical attack are the polyunsaturated fatty acids of cell membranes causing lipid peroxidation. The free radicals are neutralized by the exogenous and endogenous antioxidant systems. Oxidative stress occurs when large number of free radicals are produced or the antioxidant activity is impaired. The present study is focused to find out the role of oxidative stress in ageing.Methods: A cross sectional observational study was undertaken to assess the oxidative stress in ageing; by determining the levels of lipid peroxidation product- malondialdehyde (MDA), the antioxidants- superoxide dismutase (SOD) and ceruloplasmin in various age groups. 150 healthy subjects were selected randomly and categorised into three different age groups of 20-30 years, 40-59 years and 60-90 years; with 50 subjects in each group. Results were expressed as mean ± standard deviation.Results: a significant elevation in serum MDA level and a decline in SOD were observed in 40-59 years and 60-90 years age groups. However, an elevated ceruloplasmin level was found in the above age groups.Conclusions: Aforementioned observations are suggestive of an association between oxidative stress and the progression of ageing process.


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Makoto Suzuki ◽  
D. Craig Willcox ◽  
Matthew W. Rosenbaum ◽  
Bradley J. Willcox

Background. The Free Radical Theory of Aging mechanistically links oxidative stress to aging. Okinawa has among the world's longest-lived populations but oxidative stress in this population has not been well characterized.Methods. We compared plasma lipid peroxide (LPO) and vitamin E—plasma and intracellular tocopherol levels (total α, β, and γ), in centenarians with younger controls.Results. Both LPO and vitamin E tocopherols were lower in centenarians, with the exception of intracellular β-tocopherol, which was significantly higher in centenarians versus younger controls. There were no significant differences between age groups for tocopherol: cholesterol and tocopherol: LPO ratios. Correlations were found between α-Tocopherol and LPO in septuagenarians but not in centenarians.Conclusions. The low plasma level of LPO in Okinawan centenarians, compared to younger controls, argues for protection against oxidative stress in the centenarian population and is consistent with the predictions of the Free Radical Theory of Aging. However, the present work does not strongly support a role for vitamin E in this phenomenon. The role of intracellular β-tocopherol deserves additional study. More research is needed on the contribution of oxidative stress and antioxidants to human longevity.


2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Andrew D. Johnston ◽  
Paul R. Ebert

Oxidative stress is a toxic state caused by an imbalance between the production and elimination of reactive oxygen species (ROS). ROS cause oxidative damage to cellular components such as proteins, lipids, and nucleic acids. While the role of ROS in cellular damage is frequently all that is noted, ROS are also important in redox signalling. The “Redox Hypothesis" has been proposed to emphasize a dual role of ROS. This hypothesis suggests that the primary effect of changes to the redox state is modified cellular signalling rather than simply oxidative damage. In extreme cases, alteration of redox signalling can contribute to the toxicity of ROS, as well as to ageing and age-related diseases. The nematode speciesCaenorhabditis elegansprovides an excellent model for the study of oxidative stress and redox signalling in animals. We use protein sequences from central redox systems inHomo sapiens,Drosophila melanogaster, andSaccharomyces cerevisiaeto query Genbank for homologous proteins inC. elegans. We then use maximum likelihood phylogenetic analysis to compare protein families betweenC. elegansand the other organisms to facilitate future research into the genetics of redox biology.


2021 ◽  
Author(s):  
zhen lin ◽  
libin ni ◽  
cheng teng ◽  
zhao zhang ◽  
xinlei lu ◽  
...  

Intervertebral disc degeneration (IDD) increases the risk of low back pain (LBP). Oxidative stress may induce cellular damage and contribute to various diseases including IDD. Endoplasmic reticulum autophagy (ER-phagy) is a specific type of autophagy, its role in oxidative stress induced damage as well as in IDD is unknown. This study explores the role of ER-phagy in oxidative damage in intervertebral disc nucleus pulposus cells (NPCs), as well as the Nrf2/FAM134B axis in ER-phagy regulation and IDD therapy. We found ER-phagy was decreased in NPCs during oxidative stress; while FAM134B may promote ER-phagy and alleviate oxidative stress induced ER-stress and apoptosis. In addition, the nuclear transcription factor Nrf2 may promote the expression of FAM134B as well as ER-phagy, and suppress ER-stress and apoptosis in NPCs. Furthermore, overexpression of FAM134B and Nrf2 could effectively attenuate the progression of IDD in rats in vivo. These results suggest Nrf2/FAM134B mediated ER-phagy may combat oxidative damage in cells; meanwhile, ER-phagy as well as Nrf2 could be potential therapeutic targets for IDD.


Author(s):  
Olga Kal’dinova ◽  
Inna Desyatirkina ◽  
Galina Sroslova ◽  
Yuliya Zimina

The paper presents a brief overview of the problems in studying the aging under the influence of oxidative reactions in the Human body. The features of the free radical theory of aging were analyzed, the role of antioxidant enzymes was considered. Aging is a complex of processes and phenomena occurring in the Human body under the influence of various factors, the oxidative metabolism has an important role in this process. The study of the mechanisms of aging opens up the prospect of using this knowledge to find methods to prolong human life.


2021 ◽  
Vol 22 (11) ◽  
pp. 5675
Author(s):  
Jinglong Chen ◽  
Danping Wang ◽  
Yibo Zong ◽  
Xiaojing Yang

Oxidative stress occurs in a variety of clinical liver diseases and causes cellular damage and mitochondrial dysfunction. The clearance of damaged mitochondria by mitophagy may facilitate mitochondrial biogenesis and enhance cell survival. Although the supplementation of docosahexaenoic acid (DHA) has been recognized to relieve the symptoms of various liver diseases, the antioxidant effect of DHA in liver disease is still unclear. The purpose of our research was to investigate the antioxidant effect of DHA in the liver and the possible role of mitophagy in this. In vitro, H2O2-induced injury was caused in AML12 cells. The results showed that DHA repressed the level of reactive oxygen species (ROS) induced by H2O2 and stimulated the cellular antioxidation response. Most notably, DHA restored oxidative stress-impaired autophagic flux and promoted protective autophagy. In addition, PINK/Parkin-mediated mitophagy was activated by DHA in AML12 cells and alleviated mitochondrial dysfunction. The ERK1/2 signaling pathway was inhibited during oxidative stress but reactivated by DHA treatment. It was proven that the expression of ERK1/2 was involved in the regulation of mitophagy by the ERK1/2 inhibitor. We further proved these results in vivo. DHA effectively alleviated the liver oxidative damage caused by CCl4 and enhanced antioxidation capacity; intriguingly, autophagy was also activated. In summary, our data demonstrated that DHA protected hepatocytes from oxidative damage through GPR120/ERK-mediated mitophagy.


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