scholarly journals Age-Associated Changes in Antioxidants and Redox Proteins of Rat Heart

2019 ◽  
pp. 883-892
Author(s):  
P. Kaplán ◽  
Z. Tatarková ◽  
L. Lichardusová ◽  
M. Kmeťová Sivoňová ◽  
A. Tomašcová ◽  
...  

Oxidative stress and decline in cellular redox regulation have been hypothesized to play a key role in cardiovascular aging; however, data on antioxidant and redox regulating systems in the aging heart are controversial. The aim of the present study was to examine the effect of aging on critical antioxidant enzymes and two major redox-regulatory systems glutathione (GSH) and thioredoxin (Trx) system in hearts from adult (6-month-old), old (15-month-old), and senescent (26-month-old) rats. Aging was associated with a non-uniform array of changes, including decline in contents of reduced GSH and total mercaptans in the senescent heart. The activities of Mn-superoxide dismutase (SOD2), glutathione peroxidase (GPx), glutathione reductase (GR), and thioredoxin reductase (TrxR) exhibited an age-related decline, whereas catalase was unchanged and Cu,Zn-superoxide dismutase (SOD1) displayed only slight decrease in old heart and was unchanged in the senescent heart. GR, Trx, and peroxiredoxin levels were significantly reduced in old and/or senescent hearts, indicating a diminished expression of these proteins. In contrast, SOD2 level was unchanged in the old heart and was slightly elevated in the senescent heart. Decline in GPx activity was accompanied by a loss of GPx level only in old rats, the level in senescent heart was unchanged. These results indicate age-related posttranslational protein modification of SOD2 and GPx. In summary, our data suggest that changes are more pronounced in senescent than in old rat hearts and support the view that aging is associated with disturbed redox balance that could alter cellular signaling and regulation.

2009 ◽  
Vol 297 (3) ◽  
pp. H1087-H1095 ◽  
Author(s):  
Lori S. Kang ◽  
Rafael A. Reyes ◽  
Judy M. Muller-Delp

Aging contributes significantly to the development of cardiovascular disease and is associated with elevated production of reactive oxygen species (ROS). The beneficial effects of nitric oxide (NO)-mediated vasodilation are quickly abolished in the presence of ROS, and this effect may be augmented with aging. We previously demonstrated an age-induced impairment of flow-induced dilation in rat coronary arterioles. Therefore, the purpose of this study was to determine the effects of O2− scavenging, as well as removal of H2O2, the byproduct of O2− scavenging, on flow-mediated dilation in coronary resistance arterioles of young (4 mo) and old (24 mo) male Fischer 344 rats. Flow increased NO and H2O2 production as evidenced by enhanced diaminofluorescein and dichlorodihydrofluorescein fluorescence, respectively, whereas aging reduced flow-induced NO and H2O2 production. Endothelium-dependent vasodilation was evaluated by increasing intraluminal flow (5–60 nl/s) before and after treatment with the superoxide dismutase mimetic Tempol (100 μM), the H2O2 scavenger catalase (100 U/ml), or Tempol plus catalase. Catalase reduced flow-induced dilation in both groups, whereas Tempol and Tempol plus catalase diminished vasodilation in young but not old rats. Tempol plus deferoxamine (100 μM), an inhibitor of hydroxyl radical formation, reversed Tempol-mediated impairment of flow-induced vasodilation in young rats and improved flow-induced vasodilation in old rats compared with control. Immunoblot analysis revealed increases in endogenous superoxide dismutase, catalase, and nitrotyrosine protein levels with aging. Collectively, these data indicate that NO- and H2O2-mediated flow-induced signaling decline with age in coronary arterioles and that elevated hydroxyl radical formation contributes to the age-related impairment of flow-induced vasodilation.


2020 ◽  
Vol 100 (4) ◽  
pp. 1599-1619 ◽  
Author(s):  
Hui-Ming Chang ◽  
Edward T. H. Yeh

Sentrin/small ubiquitin-like modifier (SUMO) is protein modification pathway that regulates multiple biological processes, including cell division, DNA replication/repair, signal transduction, and cellular metabolism. In this review, we will focus on recent advances in the mechanisms of disease pathogenesis, such as cancer, diabetes, seizure, and heart failure, which have been linked to the SUMO pathway. SUMO is conjugated to lysine residues in target proteins through an isopeptide linkage catalyzed by SUMO-specific activating (E1), conjugating (E2), and ligating (E3) enzymes. In steady state, the quantity of SUMO-modified substrates is usually a small fraction of unmodified substrates due to the deconjugation activity of the family Sentrin/SUMO-specific proteases (SENPs). In contrast to the complexity of the ubiquitination/deubiquitination machinery, the biochemistry of SUMOylation and de-SUMOylation is relatively modest. Specificity of the SUMO pathway is achieved through redox regulation, acetylation, phosphorylation, or other posttranslational protein modification of the SUMOylation and de-SUMOylation enzymes. There are three major SUMOs. SUMO-1 usually modifies a substrate as a monomer; however, SUMO-2/3 can form poly-SUMO chains. The monomeric SUMO-1 or poly-SUMO chains can interact with other proteins through SUMO-interactive motif (SIM). Thus SUMO modification provides a platform to enhance protein-protein interaction. The consequence of SUMOylation includes changes in cellular localization, protein activity, or protein stability. Furthermore, SUMO may join force with ubiquitin to degrade proteins through SUMO-targeted ubiquitin ligases (STUbL). After 20 yr of research, SUMO has been shown to play critical roles in most, if not all, biological pathways. Thus the SUMO enzymes could be targets for drug development to treat human diseases.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1916-P
Author(s):  
REBECCA L. SCALZO ◽  
GRAHAME F. EVANS ◽  
SARA E. HULL ◽  
LESLIE KNAUB ◽  
LORI A. WALKER ◽  
...  

Author(s):  
И.Д. Габдрахманова ◽  
В.А. Мышкин ◽  
Д.А. Еникеев ◽  
А.Р. Гимадиева

Цель исследования: изучение влияния сукцината 1,3,6-триметил-5-гидроксиурацила на антиоксидантную систему и свободнорадикальные процессы в печени взрослых и старых крыс при воздействии тетрахлорметана. Методика. В эксперименте использованы половозрелые животные 12-месячного возраста со средней массой 250 г и старые животные 24-месячного возраста, средней массой 395 г по 30 особей в каждой возрастной группе. Токсическое поражение печени вызывали подкожным введением 50%-ного масляного раствора тетрахлорметана (ТХМ, 2 г/кг) в течение 4 сут. Одновременно с токсикантом опытным животным внутрибрюшинно вводили водный раствор коплексного соединения сукцинат-1,3,6-триметил-5-гидроксиурацила (2,5 мг/100 г) 3 раза в сут. в течение первых 4 сут. и в течение последующих 3 сут. 1 раз в сут. Контролем служили опытные животные, которым вводили физиологический раствор в том же объеме. Изучали окислительную модификацию белков, перекисное окисление липидов (по содержанию ТБК-реагирующих продуктов, уровню гидроперекисей липидов и содержанию диеновых конъюгатов). Состояние антиоксидантной системы оценивали по активности ферментов супероксиддисмутазы, каталазы и глутатионпероксидазы, определяемых биохимическими методами. Антирадикальную активность комплексного соединения и его составляющих субстанций исследовали в модельной системе «этилбензол-ледяная уксусная кислота» с вычислением константы К - скорости взаимодействия перекисных радикалов с молекулами изучаемого соединения в сравнении с эталонным антиоксидантом-ионолом с витамином Е. Результаты. Сукцинат + 1,3,6-триметил-5-гидрокси-урацила существенно снижает токсическое действие ТХМ на печень взрослых и старых крыс, устраняет дисбаланс в системах свободнорадикального окисления белков у старых крыс, статистически значимо улучшает показатели свободнорадикального окисления (СРО) липидов в печени взрослых и старых крыс: снижает уровень продуктов ПОЛ - гидроперекисей, диеновых конъюгатов, ТБК-реагирующих продуктов, а также улучшает работу антиоксидантной системы (АОС), повышая активность каталазы, супероксиддисмутазы и глутатионпероксидазы. Установлена высокая антирадикальная активность изучаемого препарата сопоставимая с активностью эталонного антиоксиданта ионола. Заключение. Сукцинат и его производные способны выступать как индивидуальные вещества с непосредственным антирадикальным механизмом действия, а не только как стимуляторы ферментативных систем антиоксидантной защиты. Aim. To study the effect of a complex compound, 1,3,6-trimethyl-5-hydroxyuracil succinate, on the antioxidant system and free radical processes induced by carbon tetrachloride in the liver of adult and old rats. Methods. The study used sexually mature animals aged 12 months and weighing 250 g and old animals aged 24 months weighing 395 g (total n= 60, 30 rats in each age group). Toxic damage of liver was induced by subcutaneous injections of a 50% oil solution of carbon tetrachloride (CTC) at 2 g/kg for 4 days. Together with the toxicant, experimental animals were injected with a water solution of a complex compound, succinate 1,3,6-trimethyl-5-hydroxyuracil, at a dose of 2.5 mg/100 g, i.p., 3 times per day for the first 4 days and once daily for the following 3 days. Experimental animals were used as controls, which were administered saline in the same volume. Oxidative modifications of proteins, lipid peroxidation (by levels of thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, and conjugated dienes) were studied. Condition of the antioxidant system was evaluated by activities of superoxide dismutase, catalase, and glutathione peroxidase using biochemical methods. Antiradical activity of the complex compound and its components was studied in a model system of ethylbenzene-glacial acetic acid; the K7 constant of the rate of peroxide radical interaction with molecules of the studied compound was compared with the reference antioxidant ionol with vitamin E. Results. Succinate +1.3.6-trimethyl-5-hydroxyuracil, considerably reduced TXM hepatotoxicity in adult and old rats; removed the disbalance in free radical systems of protein oxidation in old rats; significantly improved indexes of free-radical oxidation (FRO) of hepatic lipids in adult and old rats; decreased levels of LP products, hydroperoxides, conjugated dienes, and TBARS, and enhanced performance of the antioxidant system (AOS) by increasing activities of catalase, superoxide dismutase, and glutathione peroxidase. The study demonstrated a high antiradical activity of the study drug comparable with the activity of the reference antioxidant, ionol. Сonclusion. Succinate and its derivatives can perform as individual substances with a direct antiradical mechanism of action rather than as stimulators of enzymic systems of antioxidant defence.


2019 ◽  
Vol 24 (40) ◽  
pp. 4726-4741 ◽  
Author(s):  
Orathai Tangvarasittichai ◽  
Surapon Tangvarasittichai

Background: Oxidative stress is caused by free radicals or oxidant productions, including lipid peroxidation, protein modification, DNA damage and apoptosis or cell death and results in cellular degeneration and neurodegeneration from damage to macromolecules. Results: Accumulation of the DNA damage (8HOdG) products and the end products of LPO (including aldehyde, diene, triene conjugates and Schiff’s bases) were noted in the research studies. Significantly higher levels of these products in comparison with the controls were observed. Oxidative stress induced changes to ocular cells and tissues. Typical changes include ECM accumulation, cell dysfunction, cell death, advanced senescence, disarrangement or rearrangement of the cytoskeleton and released inflammatory cytokines. It is involved in ocular diseases, including keratoconus, Fuchs endothelial corneal dystrophy, and granular corneal dystrophy type 2, cataract, age-related macular degeneration, primary open-angle glaucoma, retinal light damage, and retinopathy of prematurity. These ocular diseases are the cause of irreversible blindness worldwide. Conclusions: Oxidative stress, inflammation and autophagy are implicated in biochemical and morphological changes in these ocular tissues. The development of therapy is a major target for the management care of these ocular diseases.


1990 ◽  
Vol 126 (3) ◽  
pp. 461-466 ◽  
Author(s):  
M. N. Sillence ◽  
R. G. Rodway

ABSTRACT The effects of trenbolone acetate (TBA) on growth and on plasma concentrations of corticosterone were examined in male and female rats. At 5 weeks of age, rats were injected with TBA (0·8 mg/kg) dissolved in peanut oil, or with oil alone, daily for 10 days. In female rats, TBA caused an increase in weight gain (20–38%), a reduction in adrenal weight (19%) and a reduction in plasma concentrations of corticosterone (55%). In contrast, TBA-treated male rats showed no significant increase in weight gain, no significant change in adrenal weight and no reduction in plasma concentrations of corticosterone. The mechanism by which adrenal activity was suppressed in TBA-treated female rats was examined and the response compared with that to testosterone. Female rats (8 weeks old) were injected daily either with oil vehicle, TBA (0·8 mg/kg) or testosterone propionate (0·8 mg/kg). Testosterone increased weight gain (24%), but the growth response to TBA treatment was significantly greater (97%). A reduction in plasma concentrations of corticosterone (45%) was again observed in response to TBA. However, testosterone increased plasma concentrations of corticosterone (52%) above those of control values. Neither androgen affected plasma concentrations of ACTH. Finally, the effects of TBA were examined in 6-week-old female rats, to characterize further the apparent age-related increase in responsiveness. The growth response of 6-week-old rats (60–74%) was intermediate between that seen in 5- and 8-week-old animals. It is concluded that part of the anabolic activity of TBA may be related to a reduction in circulating concentrations of corticosterone. The effect of TBA on corticosterone concentrations differs from that of the natural androgen, testosterone, and does not appear to be mediated by a reduction in plasma concentrations of ACTH. Journal of Endocrinology (1990) 126, 461–466


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