scholarly journals Significance of Mitochondrial Reactive Oxygen Species in the Generation of Oxidative Stress in Spermatozoa

2008 ◽  
Vol 93 (8) ◽  
pp. 3199-3207 ◽  
Author(s):  
Adam J. Koppers ◽  
Geoffry N. De Iuliis ◽  
Jane M. Finnie ◽  
Eileen A. McLaughlin ◽  
R. John Aitken
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Complex I ◽  
Mitochondrial Membrane ◽  
Reactive Oxygen ◽  
Human Spermatozoa ◽  
Ros Generation ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Sperm Movement

Abstract Context: Male infertility has been linked with the excessive generation of reactive oxygen species (ROS) by defective spermatozoa. However, the subcellular origins of this activity are unclear. Objective: The objective of this study was to determine the importance of sperm mitochondria in creating the oxidative stress associated with defective sperm function. Method: Intracellular measurement of mitochondrial ROS generation and lipid peroxidation was performed using the fluorescent probes MitoSOX red and BODIPY C11 in conjunction with flow cytometry. Effects on sperm movement were measured by computer-assisted sperm analysis. Results: Disruption of mitochondrial electron transport flow in human spermatozoa resulted in generation of ROS from complex I (rotenone sensitive) or III (myxothiazol, antimycin A sensitive) via mechanisms that were independent of mitochondrial membrane potential. Activation of ROS generation at complex III led to the rapid release of hydrogen peroxide into the extracellular space, but no detectable peroxidative damage. Conversely, the induction of ROS on the matrix side of the inner mitochondrial membrane at complex I resulted in peroxidative damage to the midpiece and a loss of sperm movement that could be prevented by the concomitant presence of α-tocopherol. Defective human spermatozoa spontaneously generated mitochondrial ROS in a manner that was negatively correlated with motility. Simultaneous measurement of general cellular ROS generation with dihydroethidium indicated that 68% of the variability in such measurements could be explained by differences in mitochondrial ROS production. Conclusion: We conclude that the sperm mitochondria make a significant contribution to the oxidative stress experienced by defective human spermatozoa.

424. Polyunsaturated fatty acids and mitochondrial reactive oxygen species production in human spermatozoa and male infertility

2008 ◽  
Vol 20 (9) ◽  
pp. 104
Author(s):  
A. J. Koppers ◽  
R. J. Aitken
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Fatty Acids ◽  
Male Infertility ◽  
Polyunsaturated Fatty Acids ◽  
Sperm Motility ◽  
Human Spermatozoa ◽  
Ros Generation ◽  
Oxygen Species ◽  
Mitochondrial Ros

Reactive oxygen species (ROS) are traditionally considered detrimental by-products of cellular metabolism. However, ROS have conflicting roles in human spermatozoa, either as a functional mediator of sperm capacitation or generating a state of oxidative stress that is associated with male infertility. Using the probe MitoSOX Red, we have shown that defective human spermatozoa generate mitochondrial ROS in manner that was negatively correlated with motility (R2 = 0.8048). Previous research has shown higher levels of polyunsaturated fatty acids (PUFAs) in defective spermatozoa. However, the addition of PUFA to normal human spermatozoa results in increased mitochondrial ROS production (P < 0.001) and lipid peroxidation (P < 0.001) determined by MitoSOX Red and BODIPY C11 assays, as a consequence human spermatozoa also exhibited decreased sperm motility (P < 0.001). Ongoing research is currently evaluating the relationship between cellular levels of PUFAs in human spermatozoa and mitochondrial ROS generation and decreased sperm motility. This research demonstrates that mitochondrial ROS generation in human spermatozoa may have significant consequences for their function and we propose that elevated PUFA content may be a primary cause of increased oxidative stress and therefore male infertility.

scholarly journals Impacts of Oxidative Stress and Antioxidants on Semen Functions

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Amrit Kaur Bansal ◽  
G. S. Bilaspuri
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Sperm Quality ◽  
Reactive Oxygen ◽  
The Body ◽  
Atp Depletion ◽  
Contributory Factor ◽  
Ros Generation ◽  
Oxygen Species ◽  
High Concentrations

Oxidative stress (OS) has been considered a major contributory factor to the infertility. Oxidative stress is the result of imbalance between the reactive oxygen species (ROS) and antioxidants in the body which can lead to sperm damage, deformity, and eventually male infertility. Although high concentrations of the ROS cause sperm pathology (ATP depletion) leading to insufficient axonemal phosphorylation, lipid peroxidation, and loss of motility and viability but, many evidences demonstrate that low and controlled concentrations of these ROS play an important role in sperm physiological processes such as capacitation, acrosome reaction, and signaling processes to ensure fertilization. The supplementation of a cryopreservation extender with antioxidant has been shown to provide a cryoprotective effect on mammalian sperm quality. This paper reviews the impacts of oxidative stress and reactive oxygen species on spermatozoa functions, causes of ROS generation, and antioxidative strategies to reduce OS. In addition, we also highlight the emerging concept of utilizing OS as a tool of contraception.

scholarly journals Effects of Aging on Cardiac Oxidative Stress and Transcriptional Changes in Pathways of Reactive Oxygen Species Generation and Clearance

2021 ◽  
Author(s):  
Farhan Rizvi ◽  
Claudia C. Preston ◽  
Larisa Emelyanova ◽  
Mohammed Yousufuddin ◽  
Maria Viqar ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Complex I ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Functional Enrichment ◽  
Pathway Enrichment Analysis ◽  
Oxygen Species ◽  
Age Related ◽  
Ros Homeostasis

Background Age‐related heart diseases are significant contributors to increased morbidity and mortality. Emerging evidence indicates that mitochondria within cardiomyocytes contribute to age‐related increased reactive oxygen species (ROS) generation that plays an essential role in aging‐associated cardiac diseases. Methods and Results The present study investigated differences between ROS production in cardiomyocytes isolated from adult (6 months) and aged (24 months) Fischer 344 rats, and in cardiac tissue of adult (18–65 years) and elderly (>65 years) patients with preserved cardiac function. Superoxide dismutase inhibitable ferricytochrome c reduction assay (1.32±0.63 versus 0.76±0.31 nMol/mg per minute; P =0.001) superoxide and H 2 O 2 production, measured as dichlorofluorescein diacetate fluorescence (1646±428 versus 699±329, P =0.04), were significantly higher in the aged versus adult cardiomyocytes. Similarity in age‐related alteration between rats and humans was identified in mitochondrial‐electron transport chain‐complex‐I‐associated increased oxidative‐stress by MitoSOX fluorescence (53.66±18.58 versus 22.81±12.60; P =0.03) and in 4‐HNE adduct levels (187.54±54.8 versus 47.83±16.7 ng/mg protein, P =0.0063), indicative of increased peroxidation in the elderly. These differences correlated with changes in functional enrichment of genes regulating ROS homeostasis pathways in aged human and rat hearts. Functional merged collective network and pathway enrichment analysis revealed common genes prioritized in human and rat aging‐associated networks that underlay enriched functional terms of mitochondrial complex I and common pathways in the aging human and rat heart. Conclusions Aging sensitizes mitochondrial and extramitochondrial mechanisms of ROS buildup within the heart. Network analysis of the transcriptome highlights the critical elements involved with aging‐related ROS homeostasis pathways common in rat and human hearts as targets.

scholarly journals Survival Signaling by C-RAF: Mitochondrial Reactive Oxygen Species and Ca2+ Are Critical Targets

2008 ◽  
Vol 28 (7) ◽  
pp. 2304-2313 ◽  
Author(s):  
Andrey V. Kuznetsov ◽  
Julija Smigelskaite ◽  
Christine Doblander ◽  
Manickam Janakiraman ◽  
Martin Hermann ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Mitochondrial Ros ◽  
Survival Signaling ◽  
First Time

ABSTRACT Survival signaling by RAF occurs through largely unknown mechanisms. Here we provide evidence for the first time that RAF controls cell survival by maintaining permissive levels of mitochondrial reactive oxygen species (ROS) and Ca2+. Interleukin-3 (IL-3) withdrawal from 32D cells resulted in ROS production, which was suppressed by activated C-RAF. Oncogenic C-RAF decreased the percentage of apoptotic cells following treatment with staurosporine or the oxidative stress-inducing agent tert-butyl hydroperoxide. However, it was also the case that in parental 32D cells growing in the presence of IL-3, inhibition of RAF signaling resulted in elevated mitochondrial ROS and Ca2+ levels. Cell death is preceded by a ROS-dependent increase in mitochondrial Ca2+, which was absent from cells expressing transforming C-RAF. Prevention of mitochondrial Ca2+ overload after IL-3 deprivation increased cell viability. MEK was essential for the mitochondrial effects of RAF. In summary, our data show that survival control by C-RAF involves controlling ROS production, which otherwise perturbs mitochondrial Ca2+ homeostasis.

scholarly journals Oxygen Sensitivity of Mitochondrial Reactive Oxygen Species Generation Depends on Metabolic Conditions

2009 ◽  
Vol 284 (24) ◽  
pp. 16236-16245 ◽  
Author(s):  
David L. Hoffman ◽  
Paul S. Brookes
Keyword(s):  
Reactive Oxygen Species ◽  
Electron Transfer ◽  
Complex I ◽  
Reactive Oxygen ◽  
Complex Iii ◽  
Ros Generation ◽  
Oxygen Species ◽  
Quinone Oxidoreductase ◽  
Electron Transfer Flavoprotein ◽  
Metabolic Conditions

The mitochondrial generation of reactive oxygen species (ROS) plays a central role in many cell signaling pathways, but debate still surrounds its regulation by factors, such as substrate availability, [O2] and metabolic state. Previously, we showed that in isolated mitochondria respiring on succinate, ROS generation was a hyperbolic function of [O2]. In the current study, we used a wide variety of substrates and inhibitors to probe the O2 sensitivity of mitochondrial ROS generation under different metabolic conditions. From such data, the apparent Km for O2 of putative ROS-generating sites within mitochondria was estimated as follows: 0.2, 0.9, 2.0, and 5.0 μm O2 for the complex I flavin site, complex I electron backflow, complex III QO site, and electron transfer flavoprotein quinone oxidoreductase of β-oxidation, respectively. Differential effects of respiratory inhibitors on ROS generation were also observed at varying [O2]. Based on these data, we hypothesize that at physiological [O2], complex I is a significant source of ROS, whereas the electron transfer flavoprotein quinone oxidoreductase may only contribute to ROS generation at very high [O2]. Furthermore, we suggest that previous discrepancies in the assignment of effects of inhibitors on ROS may be due to differences in experimental [O2]. Finally, the data set (see supplemental material) may be useful in the mathematical modeling of mitochondrial metabolism.

scholarly journals Cross talk between increased intracellular zinc (Zn2+) and accumulation of reactive oxygen species in chemical ischemia

2017 ◽  
Vol 313 (4) ◽  
pp. C448-C459 ◽  
Author(s):  
Kira G. Slepchenko ◽  
Qiping Lu ◽  
Yang V. Li
Keyword(s):  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Cross Talk ◽  
Reactive Oxygen ◽  
Glucose Deprivation ◽  
Ros Generation ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Ros Accumulation ◽  
Ischemic Stress

Both zinc (Zn2+) and reactive oxygen species (ROS) have been shown to accumulate during hypoxic-ischemic stress and play important roles in pathological processes. To understand the cross talk between the two of them, here we studied Zn2+ and ROS accumulation by employing fluorescent probes in HeLa cells to further the understanding of the cause and effect relationship of these two important cellular signaling systems during chemical-ischemia, stimulated by oxygen and glucose deprivation (OGD). We observed two Zn2+ rises that were divided into four phases in the course of 30 min of OGD. The first Zn2+ rise was a transient, which was followed by a latent phase during which Zn2+ levels recovered; however, levels remained above a basal level in most cells. The final phase was the second Zn2+ rise, which reached a sustained plateau called Zn2+ overload. Zn2+ rises were not observed when Zn2+ was removed by TPEN (a Zn2+ chelator) or thapsigargin (depleting Zn2+ from intracellular stores) treatment, indicating that Zn2+ was from intracellular storage. Damaging mitochondria with FCCP significantly reduced the second Zn2+ rise, indicating that the mitochondrial Zn2+ accumulation contributes to Zn2+ overload. We also detected two OGD-induced ROS rises. Two Zn2+ rises preceded two ROS rises. Removal of Zn2+ reduced or delayed OGD- and FCCP-induced ROS generation, indicating that Zn2+ contributes to mitochondrial ROS generation. There was a Zn2+-induced increase in the functional component of NADPH oxidase, p47phox, thus suggesting that NADPH oxidase may mediate Zn2+-induced ROS accumulation. We suggest a new mechanism of cross talk between Zn2+ and mitochondrial ROS through positive feedback processes that eventually causes excessive free Zn2+ and ROS accumulations during the course of ischemic stress.

Mitochondrial [dys]function; culprit in pre-eclampsia?

2016 ◽  
Vol 130 (14) ◽  
pp. 1179-1184 ◽  
Author(s):  
Cathal Michael McCarthy ◽  
Louise Clare Kenny
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Mitochondrial Dysfunction ◽  
Vascular Dysfunction ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Redox Signalling ◽  
Mitochondrial Superoxide ◽  
Mitochondrial Ros ◽  
Signalling Systems

Mitochondria are extensively identified for their bioenergetic capacities; however, recently these metabolic hubs are increasingly being appreciated as critical regulators of numerous cellular signalling systems. Mitochondrial reactive oxygen species have evolved as a mode of cross-talk between mitochondrial function and physiological systems, to sustain equipoise and foster adaption to cellular stress. Redox signalling mediated by exaggerated mitochondrial-ROS (reactive oxygen species) has been incriminated in a plethora of disease pathologies. Excessive production of mitochondrial ROS is intrinsically linked to mitochondrial dysfunction. Furthermore, mitochondrial dysfunction is a key facilitator of oxidative stress, inflammation, apoptosis and metabolism. These are key pathogenic intermediaries of pre-eclampsia, hence we hypothesize that mitochondrial dysfunction is a pathogenic mediator of oxidative stress in the pathophysiology of pre-eclampsia. We hypothesize that mitochondrial-targeted antioxidants may restrain production of ROS-mediated deleterious redox signalling pathways. If our hypothesis proves correct, therapeutic strategies directly targeting mitochondrial superoxide scavenging should be actively pursued as they may alleviate maternal vascular dysfunction and dramatically improve maternal and fetal health worldwide.

scholarly journals The impact of reactive oxygen species in the development of cardiometabolic disorders: a review

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Roland Akhigbe ◽  
Ayodeji Ajayi
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Acid Oxidation ◽  
Ros Generation ◽  
Metabolic Memory ◽  
Oxygen Species ◽  
Cardiometabolic Disorders ◽  
The Impact

AbstractOxidative stress, an alteration in the balance between reactive oxygen species (ROS) generation and antioxidant buffering capacity, has been implicated in the pathogenesis of cardiometabolic disorders (CMD). At physiological levels, ROS functions as signalling mediators, regulates various physiological functions such as the growth, proliferation, and migration endothelial cells (EC) and smooth muscle cells (SMC); formation and development of new blood vessels; EC and SMC regulated death; vascular tone; host defence; and genomic stability. However, at excessive levels, it causes a deviation in the redox state, mediates the development of CMD. Multiple mechanisms account for the rise in the production of free radicals in the heart. These include mitochondrial dysfunction and uncoupling, increased fatty acid oxidation, exaggerated activity of nicotinamide adenine dinucleotide phosphate oxidase (NOX), reduced antioxidant capacity, and cardiac metabolic memory. The purpose of this study is to discuss the link between oxidative stress and the aetiopathogenesis of CMD and highlight associated mechanisms. Oxidative stress plays a vital role in the development of obesity and dyslipidaemia, insulin resistance and diabetes, hypertension via various mechanisms associated with ROS-led inflammatory response and endothelial dysfunction.

scholarly journals Regulation of Reactive Oxygen Species and Antioxidant Defense in Plants under Salinity

2021 ◽  
Vol 22 (17) ◽  
pp. 9326
Author(s):  
Mirza Hasanuzzaman ◽  
Md. Rakib Hossain Raihan ◽  
Abdul Awal Chowdhury Masud ◽  
Khussboo Rahman ◽  
Farzana Nowroz ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Salt Stress ◽  
Oxidative Damage ◽  
Antioxidant Defense ◽  
Reactive Oxygen ◽  
Antioxidant Defense System ◽  
Ros Generation ◽  
Oxygen Species ◽  
Defense System

The generation of oxygen radicals and their derivatives, known as reactive oxygen species, (ROS) is a part of the signaling process in higher plants at lower concentrations, but at higher concentrations, those ROS cause oxidative stress. Salinity-induced osmotic stress and ionic stress trigger the overproduction of ROS and, ultimately, result in oxidative damage to cell organelles and membrane components, and at severe levels, they cause cell and plant death. The antioxidant defense system protects the plant from salt-induced oxidative damage by detoxifying the ROS and also by maintaining the balance of ROS generation under salt stress. Different plant hormones and genes are also associated with the signaling and antioxidant defense system to protect plants when they are exposed to salt stress. Salt-induced ROS overgeneration is one of the major reasons for hampering the morpho-physiological and biochemical activities of plants which can be largely restored through enhancing the antioxidant defense system that detoxifies ROS. In this review, we discuss the salt-induced generation of ROS, oxidative stress and antioxidant defense of plants under salinity.

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