scholarly journals Cytochrome P450-dependent reactive oxygen species (ROS) production contributes to Mn3O4 nanoparticle-caused liver injury

RSC Advances ◽  
2018 ◽  
Vol 8 (65) ◽  
pp. 37307-37314 ◽  
Author(s):  
Zongkai Yue ◽  
Xiao Zhang ◽  
Qilin Yu ◽  
Lu Liu ◽  
Xiaomeng Zhou

Mn3O4 nanoparticles (NPs) are one of the most important nanomaterials, and have a wide range of applications (i.e., catalysis, solar-electron transformation and molecular adsorption).

2005 ◽  
Vol 289 (3) ◽  
pp. E429-E438 ◽  
Author(s):  
Lisa Bevilacqua ◽  
Jon J. Ramsey ◽  
Kevork Hagopian ◽  
Richard Weindruch ◽  
Mary-Ellen Harper

Calorie restriction (CR) without malnutrition increases life span and delays the onset of a variety of diseases in a wide range of animal species. However, the mechanisms responsible for the retardation of aging with CR are poorly understood. We proposed that CR may act, in part, by inducing a hypometabolic state characterized by decreased reactive oxygen species (ROS) production and mitochondrial proton leak. Here, we examine the effects of long-term CR on whole animal energetics as well as muscle mitochondrial energetics, ROS production, and ROS damage. CR was initiated in male FBNF1 rats at 6 mo of age and continued for 12 or 18 mo. Mean whole body V̇o2 was 34.6 ( P < 0.01) and 35.6% ( P < 0.001) lower in CR rats than in controls after 12 and 18 mo of CR, respectively. Body mass-adjusted V̇o2 was 11.1 and 29.5% lower (both P < 0.05) in CR rats than in controls after 12 and 18 mo of CR. Muscle mitochondrial leak-dependent (State 4) respiration was decreased after 12 mo compared with controls; however, after 18 mo of CR, there were slight but not statistically significant differences. Proton leak kinetics were affected by 12 mo of CR such that leak-dependent respiration was lower in CR mitochondria only at protonmotive force values exceeding 170 mV. Mitochondrial H2O2 production and oxidative damage were decreased by CR at both time points and increased with age. Muscle UCP3 protein content increased with long-term CR, consistent with a role in protection from ROS but inconsistent with the observed decrease or no change in proton leak.


2005 ◽  
Vol 37 (5) ◽  
pp. 397-407 ◽  
Author(s):  
Richard Peter BECKETT ◽  
Farida V. MINIBAYEVA ◽  
Zsanett LAUFER

This review discusses the production of reactive oxygen species (ROS) by lichens and their possible roles. All organisms produce ROS, and production is increased by many abiotic and biotic stresses. Intracellular ROS production is generally considered to be harmful, and a variety of enzymic and non-enzymic scavenging systems exist to detoxify them. However, extracellular ROS formation has been suggested to play ‘positive roles’, particularly in the response of organisms to stress. Given their high stress tolerance, it is rather surprising that studies on extracellular ROS production by lichens have just started. Surveys of a wide range of lichens have shown that constitutively high rates of extracellular superoxide production occur in the Suborder Peltigerineae, but production appears to be absent in other groups. In some members of the Peltigerineae ROS production is stimulated by desiccation and wounding. It seems probable that the enzymes that produce the superoxide are laccases, based on first the types of substrates that lichens can break down, and second the dependence of the breakdown of these substrates on pH, temperature and the presence of inhibitors. While much more work is needed, we suggest that physiological roles of extracellular ROS production will be found to include defence against pathogens, melanization, and lignin breakdown.


Author(s):  
Hanna D. Bismuth ◽  
Gaël Brasseur ◽  
Benjamin Ezraty ◽  
Laurent Aussel

Over the last decade, an increasing number of reports presented Galleria mellonella larvae as an important model to study host-pathogen interactions. Coherently, increasing information became available about molecular mechanisms used by this host to cope with microbial infections but few of them dealt with oxidative stress. In this work, we addressed the role of reactive oxygen species (ROS) produced by the immune system of G. mellonella to resist against Salmonella enterica, an intracellular pathogen responsible for a wide range of infections. We confirmed that Salmonella was pathogen for G. mellonella and showed that it had to reach a minimal bacterial load within the hemolymph to kill the larvae. ROS production by G. mellonella was revealed by the virulence defects of Salmonella mutants lacking catalases/peroxiredoxins or cytoplasmic superoxide dismutases, both strains being highly sensitive to these oxidants. Finally, we used bacterial transcriptional fusions to demonstrate that hydrogen peroxide (H2O2) was produced in the hemolymph of Galleria during infection and sensed by S. enterica. In line with this observation, the H2O2-dependent regulator OxyR was found to be required for bacterial virulence in the larvae. These results led us to conclude that ROS production is an important mechanism used by G. mellonella to counteract bacterial infections and validate this host as a relevant model to study host-pathogen interactions.


Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1586
Author(s):  
Svetlana Veselova ◽  
Tatyana Nuzhnaya ◽  
Guzel Burkhanova ◽  
Sergey Rumyantsev ◽  
Igor Maksimov

Reactive oxygen species (ROS) play a central role in plant immune responses. The most important virulence factors of the Stagonospora nodorum Berk. are multiple fungal necrotrophic effectors (NEs) (SnTox) that affect the redox-status and cause necrosis and/or chlorosis in wheat lines possessing dominant susceptibility genes (Snn). However, the effect of NEs on ROS generation at the early stages of infection has not been studied. We studied the early stage of infection of various wheat genotypes with S nodorum isolates -Sn4VD, SnB, and Sn9MN, carrying a different set of NE genes. Our results indicate that all three NEs of SnToxA, SnTox1, SnTox3 significantly contributed to cause disease, and the virulence of the isolates depended on their differential expression in plants (Triticum aestivum L.). The Tsn1–SnToxA, Snn1–SnTox1and Snn3–SnTox3 interactions played an important role in inhibition ROS production at the initial stage of infection. The Snn3–SnTox3 inhibited ROS production in wheat by affecting NADPH-oxidases, peroxidases, superoxide dismutase and catalase. The Tsn1–SnToxA inhibited ROS production in wheat by affecting peroxidases and catalase. The Snn1–SnTox1 inhibited the production of ROS in wheat by mainly affecting a peroxidase. Collectively, these results show that the inverse gene-for gene interactions between effector of pathogen and product of host sensitivity gene suppress the host’s own PAMP-triggered immunity pathway, resulting in NE-triggered susceptibility (NETS). These results are fundamentally changing our understanding of the development of this economical important wheat disease.


2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
V. Jaenen ◽  
S. Fraguas ◽  
K. Bijnens ◽  
M. Heleven ◽  
T. Artois ◽  
...  

AbstractDespite extensive research on molecular pathways controlling the process of regeneration in model organisms, little is known about the actual initiation signals necessary to induce regeneration. Recently, the activation of ERK signaling has been shown to be required to initiate regeneration in planarians. However, how ERK signaling is activated remains unknown. Reactive Oxygen Species (ROS) are well-known early signals necessary for regeneration in several models, including planarians. Still, the probable interplay between ROS and MAPK/ERK has not yet been described. Here, by interfering with major mediators (ROS, EGFR and MAPK/ERK), we were able to identify wound-induced ROS, and specifically H2O2, as upstream cues in the activation of regeneration. Our data demonstrate new relationships between regeneration-related ROS production and MAPK/ERK activation at the earliest regeneration stages, as well as the involvement of the EGFR-signaling pathway. Our results suggest that (1) ROS and/or H2O2 have the potential to rescue regeneration after MEK-inhibition, either by H2O2-treatment or light therapy, (2) ROS and/or H2O2 are required for the activation of MAPK/ERK signaling pathway, (3) the EGFR pathway can mediate ROS production and the activation of MAPK/ERK during planarian regeneration.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1243
Author(s):  
Eunus S. Ali ◽  
Grigori Y. Rychkov ◽  
Greg J. Barritt

TRPM2 channels admit Ca2+ and Na+ across the plasma membrane and release Ca2+ and Zn2+ from lysosomes. Channel activation is initiated by reactive oxygen species (ROS), leading to a subsequent increase in ADP-ribose and the binding of ADP-ribose to an allosteric site in the cytosolic NUDT9 homology domain. In many animal cell types, Ca2+ entry via TRPM2 channels mediates ROS-initiated cell injury and death. The aim of this review is to summarise the current knowledge of the roles of TRPM2 and Ca2+ in the initiation and progression of chronic liver diseases and acute liver injury. Studies to date provide evidence that TRPM2-mediated Ca2+ entry contributes to drug-induced liver toxicity, ischemia–reperfusion injury, and the progression of non-alcoholic fatty liver disease to cirrhosis, fibrosis, and hepatocellular carcinoma. Of particular current interest are the steps involved in the activation of TRPM2 in hepatocytes following an increase in ROS, the downstream pathways activated by the resultant increase in intracellular Ca2+, and the chronology of these events. An apparent contradiction exists between these roles of TRPM2 and the role identified for ROS-activated TRPM2 in heart muscle and in some other cell types in promoting Ca2+-activated mitochondrial ATP synthesis and cell survival. Inhibition of TRPM2 by curcumin and other “natural” compounds offers an attractive strategy for inhibiting ROS-induced liver cell injury. In conclusion, while it has been established that ROS-initiated activation of TRPM2 contributes to both acute and chronic liver injury, considerable further research is needed to elucidate the mechanisms involved, and the conditions under which pharmacological inhibition of TRPM2 can be an effective clinical strategy to reduce ROS-initiated liver injury.


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