Biochemie des oxidativen Stress

Sies, Helmut

doi:10.1002/ange.19860981203

Cited by 132 publications

(33 citation statements)

References 182 publications

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“…In addition to the mechanisms described here, there are various other enzymic and nonenzymic mechanisms of ROS production as reviewed elsewhere (101,122,365,526).…”

Section: Other Sources Of Rosmentioning

confidence: 99%

Free Radicals in the Physiological Control of Cell Function

Dröge

2002

Physiological Reviews

8,452

5,836

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At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents. At moderate concentrations, however, nitric oxide (NO), superoxide anion, and related reactive oxygen species (ROS) play an important role as regulatory mediators in signaling processes. Many of the ROS-mediated responses actually protect the cells against oxidative stress and reestablish “redox homeostasis.” Higher organisms, however, have evolved the use of NO and ROS also as signaling molecules for other physiological functions. These include regulation of vascular tone, monitoring of oxygen tension in the control of ventilation and erythropoietin production, and signal transduction from membrane receptors in various physiological processes. NO and ROS are typically generated in these cases by tightly regulated enzymes such as NO synthase (NOS) and NAD(P)H oxidase isoforms, respectively. In a given signaling protein, oxidative attack induces either a loss of function, a gain of function, or a switch to a different function. Excessive amounts of ROS may arise either from excessive stimulation of NAD(P)H oxidases or from less well-regulated sources such as the mitochondrial electron-transport chain. In mitochondria, ROS are generated as undesirable side products of the oxidative energy metabolism. An excessive and/or sustained increase in ROS production has been implicated in the pathogenesis of cancer, diabetes mellitus, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and other diseases. In addition, free radicals have been implicated in the mechanism of senescence. That the process of aging may result, at least in part, from radical-mediated oxidative damage was proposed more than 40 years ago by Harman ( J Gerontol 11: 298–300, 1956). There is growing evidence that aging involves, in addition, progressive changes in free radical-mediated regulatory processes that result in altered gene expression.

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“…In addition to the mechanisms described here, there are various other enzymic and nonenzymic mechanisms of ROS production as reviewed elsewhere (101,122,365,526).…”

Section: Other Sources Of Rosmentioning

confidence: 99%

Free Radicals in the Physiological Control of Cell Function

Dröge

2002

Physiological Reviews

8,452

5,836

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“…Unspecific oxidation of lipids 'lipidperoxidation' commences with lipid radical production and leads to the accumulation of stable degradation products, such as malondialdehyde (Sies, 1986). During exercise elevated metabolic rates can lead to higher ROS generation and thus higher lipidperoxidation.…”

Section: Lipidperoxidation In Ageing Growth and Exercisementioning

confidence: 99%

Size- and age-dependent changes in adductor muscle swimming physiology of the scallopAequipecten opercularis

Philipp

Schmidt

Gsottbauer

et al. 2008

Journal of Experimental Biology

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SUMMARYThe decline of cellular and especially mitochondrial functions with age is, among other causes, held responsible for a decrease in physiological fitness and exercise capacity during lifetime. We investigated size-and age-related changes in the physiology of exercising specimens of the short lived swimming scallop Aequipecten opercularis (maximum life span 8 to 10 years) from the Isle of Man, UK. A. opercularis swim mainly to avoid predators, and a decrease in swimming abilities would increase the risk of capture and lower the rates of survival. Bigger (older) individuals were found to have lower mitochondrial volume density and aerobic capacities (citrate synthase activity and adenylates) as well as less anaerobic capacity deduced from the amount of glycogen stored in muscle tissue. Changes in redox potential, tissue pH and the loss of glutathione in the swimming muscle during the exercise were more pronounced in young compared to older individuals. This indicates that older individuals can more effectively stabilize cellular homeostasis during repeated exercise than younger animals but with a possible fitness cost as the change in physiology with age and size might result in a changed escape response behaviour towards predators. Supplementary material available online at

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“…Aerobic organisms are exposed to reactive oxygen species (ROS), 1 which are generated as by-products of their metabolism throughout their lives. ROS are combated by the organism with antioxidative systems, which include enzymes such as superoxide dismutase, catalase, and peroxidases as well as non-enzymatic antioxidants like glutathione and vitamins E and C (1).…”

mentioning

confidence: 99%

“…ROS are combated by the organism with antioxidative systems, which include enzymes such as superoxide dismutase, catalase, and peroxidases as well as non-enzymatic antioxidants like glutathione and vitamins E and C (1). These antioxidants prevent damage of nucleic acids, proteins, and membrane integrity and are crucial for the survival in an aerobic environment (1,2). Parasites have not only to cope with the oxidative stress generated by their own metabolic reactions but also have to fight ROS generated by the host immune system.…”

mentioning

confidence: 99%

Thioredoxin Reductase Is Essential for the Survival ofPlasmodium falciparum Erythrocytic Stages

Krnajski¹,

Gilberger²,

Walter³

et al. 2002

Journal of Biological Chemistry

103

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The human malaria parasite Plasmodium falciparum poses an increasing threat to human health in the tropical regions of the world, and the validation and assessment of possible drug targets is required for the development of new antimalarials. It has been shown that the erythrocytic stages of the parasites, which are responsible for the pathology of the disease in humans, are under enhanced oxidative stress and are particularly vulnerable to exogenous challenges by reactive oxygen species. Therefore it is postulated that the disruption of the antioxidant and/or redox systems of the parasite is a feasible way to interfere with their development during erythrocytic schizogony. In order to test this suggestion thioredoxin reductase (TrxR), an enzyme heavily involved in maintenance of redox homeostasis and antioxidant defense, was knocked out in P. falciparum. It was impossible to generate parasites with a disrupted trxR gene suggesting that TrxR is essential for P. falciparum erythrocytic stages. Technical problems were excluded by transfecting a 3 replacement construct, which recombined correctly and transfectants did not show any phenotypic alterations. In order to prove that the trxR knockout was responsible for the lethal phenotype of the null mutants, a co-transfection with both the knockout construct and a construct containing the trxR coding region under the control of the calmodulin promoter was conducted. Despite the disruption of the trxR gene, parasites were viable. In a Southern blot analysis a complicated restriction pattern was obtained, but it was shown by pulse field gel electrophoresis and field inverse gel electrophoreses that only the trxR gene locus on chromosome 9 was targeted by the constructs. It was found that the co-transfected constructs form concatemeric structures prior to integration into the trxR gene locus, which is further supported by plasmid rescue followed by restriction analyses of the plasmids. Northern and Western blot analyses proved that the co-transfectants highly overexpress TrxR from the introduced gene. Our results demonstrate that TrxR is essential for the survival of the erythrocytic stages of P. falciparum.

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Biochemie des oxidativen Stress

Cited by 132 publications

References 182 publications

Free Radicals in the Physiological Control of Cell Function

Free Radicals in the Physiological Control of Cell Function

Size- and age-dependent changes in adductor muscle swimming physiology of the scallopAequipecten opercularis

Thioredoxin Reductase Is Essential for the Survival ofPlasmodium falciparum Erythrocytic Stages

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