Search results for "OXIDATION"
showing 10 items of 1913 documents
Respiratory chain cysteine and methionine usage indicate a causal role for thiyl radicals in aging
2011
The identification of longevity-related structural adaptations in biological macromolecules may yield relevant insights into the molecular mechanisms of aging. In screening fully sequenced animal proteomes for signals associated with longevity, it was found that cysteine depletion in respiratory chain complexes was the by far strongest predictor on the amino acid usage level to co-vary with lifespan. This association was though restricted to aerobic animals, whereas anaerobic animals showed variable cysteine accumulation. By contrast, methionine accumulation, a prominent feature of mitochondrially encoded proteins affording competitive antioxidant protection, was not predictive of longevity…
Alteration in Redox Status and Lipoprotein Profile in COVID-19 Patients with Mild, Moderate, and Severe Pneumonia
2022
Background. Metabolic alterations, particularly disorders of lipoprotein metabolism in COVID-19, may affect the course and outcome of the disease. This study aims at evaluating the lipoprotein profile and redox status in SARS-CoV-2 infected patients with different pneumonia severity and their association with lethal outcomes. Methods. The prospective cohort study was performed on 98 COVID-19 patients with mild, moderate, and severe pneumonia. Lipid and inflammatory parameters, lipoprotein subclasses, and redox status biomarkers were determined at the study entry and after one week. Results. Compared to patients with mild and moderate pneumonia, severely ill patients had higher oxidised low-…
Repair of oxidatively generated DNA damage in Cockayne syndrome
2013
Defects in the repair of endogenously (especially oxidatively) generated DNA modifications and the resulting genetic instability can potentially explain the clinical symptoms of Cockayne syndrome (CS), a hereditary disease characterized by developmental defects and neurological degeneration. In this review, we describe the evidence for the involvement of CSA and CSB proteins, which are mutated in most of the CS patients, in the repair and processing of DNA damage induced by reactive oxygen species and the implications for the induction of cell death and mutations. Taken together, the data demonstrate that CSA and CSB, in addition to their established role in transcription-coupled nucleotide…
Mitochondrial oxidative stress plays a key role in aging and apoptosis
2000
Harman first suggested in 1972 that mitochondria might be the biological clock in aging, noting that the rate of oxygen consumption should determine the rate of accumulation of mitochondrial damage produced by free radical reactions. Later in 1980 Miquel and coworkers proposed the mitochondrial theory of cell aging. Mitochondria from postmitotic cells use O2 at a high rate, hence releasing oxygen radicals that exceed the cellular antioxidant defences. The key role of mitochondria in cell aging has been outlined by the degeneration induced in cells microinjected with mitochondria isolated from fibroblasts of old rats, especially by the inverse relationship reported between the rate of mitoch…
Mitochondria, oxidative stress and aging
2000
In the eighties, Miquel and Fleming suggested that mitochondria play a key role in cellular aging. Mitochondria, and specially mitochondrial DNA (mtDNA), are major targets of free radical attack. At present, it is well established that mitochondrial deficits accumulate upon aging due to oxidative damage. Thus, oxidative lesions to mtDNA accumulate with age in human and rodent tissues. Furthermore, levels of oxidative damage to mtDNA are several times higher than those of nuclear DNA. Mitochondrial size increases whereas mitochondrial membrane potential decreases with age in brain and liver. Recently, we have shown that treatment with certain antioxidants, such as sulphur-containing antioxid…
Reduced In Vivo Aortic Uptake of Radiolabeled Oxidation-Specific Antibodies Reflects Changes in Plaque Composition Consistent With Plaque Stabilizati…
2004
Objective— Labeled oxidation-specific antibodies (Ox-AB) detect, quantify, and noninvasively image lipid-rich atherosclerotic lesions. However, it is unknown whether Ox-AB detect plaque stabilization. Methods and Results— The aortic uptake of intravenously injected 125 I-MDA2 (Ox-AB to malondialdehyde [MDA]–low-density lipoprotein [LDL]) was quantitated in: (1) LDL receptor−/− mice with established atherosclerosis continued on Western diet (Progression) or switched to chow (Regression) or chow+vitamins E and C (Regression-VIT) for 6 months; and (2) Watanabe rabbits (3- to 57-months old) with naturally evolved atherosclerotic lesions. In mice, the Progression group had more extensive athero…
Differential cysteine depletion in respiratory chain complexes enables the distinction of longevity from aerobicity.
2010
Mitochondrially encoded proteins in long-lived animals exhibit a characteristic anomaly on the amino acid usage level: they abstain from the use of cysteine in a lifespan-dependent fashion. Here, we have further investigated this phenomenon by analyzing respiratory chain complex subunits individually. We find that complex I cysteine depletion is the almost exclusive carrier of the cysteine-lifespan correlation, whereas complex IV cysteine depletion is uniform in all aerobic animals, unrelated to longevity, but even more pronounced than complex I cysteine depletion in the longest-lived species. In nuclear encoded subunits of the respiratory chain, we find lifespan-independent cysteine deplet…
The Effect of Moderate- Versus High-Intensity Resistance Training on Systemic Redox State and DNA Damage in Healthy Older Women
2018
This study investigated effects of a 16-week progressive resistance training program (RTP) with elastic bands at two different intensities on systemic redox state, DNA damage, and physical function in healthy older women. Methods: Participants were randomly assigned to the high-intensity group (HIGH; n = 39), moderate-intensity group (MOD; n = 31), or control group (CG; n = 23). The exercise groups performed an RTP twice a week with three to four sets of 6 (HIGH) or 15 (MOD) repetitions of six overall body exercises at a perceived exertion rate of 8–9 on the OMNI-Resistance Exercise Scale for use with elastic bands. Thiol redox state was determined by reduced glutathione (GSH), oxidized gl…
Tuning The Selectivity To Aldehyde Via Ph Regulation In The Photocatalytic Oxidation Of 4-Methoxybenzyl Alcohol And Vanillyl Alcohol By Tio2 Catalysts
2021
Abstract The influence of pH on the photocatalytic partial oxidation of 4-methoxybenzyl alcohol (MBA) and vanillyl alcohol (VA) to their corresponding aldehydes in aqueous suspension under UVA irradiation was investigated by using poorly crystalline home-prepared and crystalline commercial TiO2 (BDH, Merck and Degussa P25) photocatalysts. The results clearly show as tuning pH can strongly impart selectivity and activity to photocatalytic processes which are often quite unselective in aqueous suspensions. It was found that pH effect on reaction rate and product selectivity strongly depended on TiO2 crystallinity and substrate type. In the case of MBA oxidation, photoreactivity and selectivit…
Glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2). New evidence for differential expres…
2011
Epidemiological and experimental studies support the involvement of lipid peroxidation (LPO) in retinal diseases. In addition to other pathogenic mechanisms not fully understood, the possibility remains that peroxidic aldehydes, acting as cytotoxic chemicals, mediate in the progression of chronic ocular disorders.To test proper mechanisms involved in removing peroxidic aldehydes from the retina, in an attempt to understand long-lasting changes induced by LPO, the oxidative and antioxidant enzymatic activities, as well as the retinal distribution and activity of glutathione-dependent formaldehyde dehydrogenase (ADH3) and low km mitochondrial aldehyde dehydrogenase (ALDH2), were studied and c…