scholarly journals Basal superoxide as a sex-specific immune constraint

2011 ◽  
Vol 7 (6) ◽  
pp. 906-908 ◽  
Author(s):  
Michael Tobler ◽  
Mo Healey ◽  
Mark Wilson ◽  
Mats Olsson

There is increasing evidence that reactive oxygen species (ROS), a group of unstable and highly reactive chemical molecules, play a key role in regulating and maintaining life-history trade-offs. Upregulation of ROS in association with immune activation is costly because it may result in an imbalance between pro- and antioxidants and, hence, oxidative damage. Previous research aimed at quantifying this cost has mostly focused on changes in the pro-/antioxidant balance subsequent to an immune response. Here, we test the hypothesis that systemic ROS may constrain immune activation. We show that systemic, pre-challenge superoxide (SO) levels are negatively related to the strength of the subsequent immune response towards the mitogen phytohaemagglutinin in male, but not female painted dragon lizards ( Ctenophorus pictus ). We therefore suggest that systemic SO constrains immune activation in painted dragon males. We speculate that this may be due to sex-specific selection pressures on immune investment.

2009 ◽  
Vol 276 (1663) ◽  
pp. 1737-1745 ◽  
Author(s):  
Damian K. Dowling ◽  
Leigh W. Simmons

Evolutionary theory is firmly grounded on the existence of trade-offs between life-history traits, and recent interest has centred on the physiological mechanisms underlying such trade-offs. Several branches of evolutionary biology, particularly those focusing on ageing, immunological and sexual selection theory, have implicated reactive oxygen species (ROS) as profound evolutionary players. ROS are a highly reactive group of oxygen-containing molecules, generated as common by-products of vital oxidative enzyme complexes. Both animals and plants appear to intentionally harness ROS for use as molecular messengers to fulfil a wide range of essential biological processes. However, at high levels, ROS are known to exert very damaging effects through oxidative stress. For these reasons, ROS have been suggested to be important mediators of the cost of reproduction, and of trade-offs between metabolic rate and lifespan, and between immunity, sexual ornamentation and sperm quality. In this review, we integrate the above suggestions into one life-history framework, and review the evidence in support of the contention that ROS production will constitute a primary and universal constraint in life-history evolution.


2020 ◽  
Vol 21 (5) ◽  
pp. 477-498
Author(s):  
Yongfeng Chen ◽  
Xingjing Luo ◽  
Zhenyou Zou ◽  
Yong Liang

Reactive oxygen species (ROS), an important molecule inducing oxidative stress in organisms, play a key role in tumorigenesis, tumor progression and recurrence. Recent findings on ROS have shown that ROS can be used to treat cancer as they accelerate the death of tumor cells. At present, pro-oxidant drugs that are intended to increase ROS levels of the tumor cells have been widely used in the clinic. However, ROS are a double-edged sword in the treatment of tumors. High levels of ROS induce not only the death of tumor cells but also oxidative damage to normal cells, especially bone marrow hemopoietic cells, which leads to bone marrow suppression and (or) other side effects, weak efficacy of tumor treatment and even threatening patients’ life. How to enhance the killing effect of ROS on tumor cells while avoiding oxidative damage to the normal cells has become an urgent issue. This study is a review of the latest progress in the role of ROS-mediated programmed death in tumor treatment and prevention and treatment of oxidative damage in bone marrow induced by ROS.


2010 ◽  
Vol 108 (4) ◽  
pp. 780-787 ◽  
Author(s):  
Kent Sahlin ◽  
Irina G. Shabalina ◽  
C. Mikael Mattsson ◽  
Linda Bakkman ◽  
Maria Fernström ◽  
...  

Exercise-induced oxidative stress is important for the muscular adaptation to training but may also cause muscle damage. We hypothesized that prolonged exercise would increase mitochondrial production of reactive oxygen species (ROS) measured in vitro and that this correlates with oxidative damage. Eight male athletes (24–32 yr) performed ultraendurance exercise (kayaking/running/cycling) with an average work intensity of 55% V̇o2peak for 24 h. Muscle biopsies were taken from vastus lateralis before exercise, immediately after exercise, and after 28 h of recovery. The production of H2O2 was measured fluorometrically in isolated mitochondria with the Amplex red and peroxidase system. Succinate-supported mitochondrial H2O2 production was significantly increased after exercise (73% higher, P = 0.025) but restored to the initial level at recovery. Plasma level of free fatty acids (FFA) increased fourfold and exceeded 1.2 mmol/l during the last 6 h of exercise. Plasma FFA at the end of exercise was significantly correlated to mitochondrial ROS production ( r = 0.74, P < 0.05). Mitochondrial content of 4-hydroxy-nonenal-adducts (a marker of oxidative damage) was increased only after recovery and was not correlated with mitochondrial ROS production. Total thiol group level and glutathione peroxidase activity were elevated after recovery. In conclusion, ultraendurance exercise increases ROS production in isolated mitochondria, but this is reversed after 28 h recovery. Mitochondrial ROS production was not correlated with oxidative damage of mitochondrial proteins, which was increased at recovery but not immediately after exercise.


2012 ◽  
Vol 80 (11) ◽  
pp. 3892-3899 ◽  
Author(s):  
Azad Eshghi ◽  
Kristel Lourdault ◽  
Gerald L. Murray ◽  
Thanatchaporn Bartpho ◽  
Rasana W. Sermswan ◽  
...  

ABSTRACTPathogenicLeptospiraspp. are likely to encounter higher concentrations of reactive oxygen species induced by the host innate immune response. In this study, we characterizedLeptospira interroganscatalase (KatE), the only annotated catalase found within pathogenicLeptospiraspecies, by assessing its role in resistance to H2O2-induced oxidative stress and during infection in hamsters. PathogenicL. interrogansbacteria had a 50-fold-higher survival rate under H2O2-induced oxidative stress than did saprophyticL. biflexabacteria, and this was predominantly catalase dependent. We also characterized KatE, the only annotated catalase found within pathogenicLeptospiraspecies. Catalase assays performed with recombinant KatE confirmed specific catalase activity, while protein fractionation experiments localized KatE to the bacterial periplasmic space. The insertional inactivation ofkatEin pathogenicLeptospirabacteria drastically diminished leptospiral viability in the presence of extracellular H2O2and reduced virulence in an acute-infection model. Combined, these results suggest thatL. interrogansKatE confersin vivoresistance to reactive oxygen species induced by the host innate immune response.


2016 ◽  
Vol 473 (12) ◽  
pp. 1769-1775 ◽  
Author(s):  
Zhongxin Ma ◽  
Heather R. Williamson ◽  
Victor L. Davidson

The present study describes how oxidative damage to a protein may occur without direct contact with a reactive oxygen species, and how that radical-mediated damage can be propagated through the protein. This process is coupled to the reactivity of high-valent haems within the same protein.


2013 ◽  
Vol 457 (2) ◽  
pp. 361-368 ◽  
Author(s):  
Jessica Coblentz ◽  
Claudette St. Croix ◽  
Kirill Kiselyov

TRPML1 is a lysosomal ion channel permeable to cations, including Fe2+. Our data suggest that TRPML1 redistributes Fe2+ between the lysosomes and the cytoplasm. Loss of TRPML1 leads to production of reactive oxygen species, and to mitochondrial deterioration.


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