scholarly journals Comparing Early Eukaryotic Integration of Mitochondria and Chloroplasts in the Light of Internal ROS Challenges: Timing is of the Essence

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Dave Speijer ◽  
Michael Hammond ◽  
Julius Lukeš
Keyword(s):  
Reactive Oxygen Species ◽  
Driving Forces ◽  
Reactive Oxygen ◽  
High Energy ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Transport Chain ◽  
Evolutionary Trajectories ◽  
Ros Formation

ABSTRACT When trying to reconstruct the evolutionary trajectories during early eukaryogenesis, one is struck by clear differences in the developments of two organelles of endosymbiotic origin: the mitochondrion and the chloroplast. From a symbiogenic perspective, eukaryotic development can be interpreted as a process in which many of the defining eukaryotic characteristics arose as a result of mutual adaptions of both prokaryotes (an archaeon and a bacterium) involved. This implies that many steps during the bacterium-to-mitochondrion transition trajectory occurred in an intense period of dramatic and rapid changes. In contrast, the subsequent cyanobacterium-to-chloroplast development in a specific eukaryotic subgroup, leading to the photosynthetic lineages, occurred in a full-fledged eukaryote. The commonalities and differences in the two trajectories shed an interesting light on early, and ongoing, eukaryotic evolutionary driving forces, especially endogenous reactive oxygen species (ROS) formation. Differences between organellar ribosomes, changes to the electron transport chain (ETC) components, and mitochondrial codon reassignments in nonplant mitochondria can be understood when mitochondrial ROS formation, e.g., during high energy consumption in heterotrophs, is taken into account. IMPORTANCE The early eukaryotic evolution was deeply influenced by the acquisition of two endosymbiotic organelles - the mitochondrion and the chloroplast. Here we discuss the possibly important role of reactive oxygen species in these processes.

scholarly journals PLA2dependence of diaphragm mitochondrial formation of reactive oxygen species

2000 ◽  
Vol 89 (1) ◽  
pp. 72-80 ◽  
Author(s):  
D. Nethery ◽  
L. A. Callahan ◽  
D. Stofan ◽  
R. Mattera ◽  
A DiMarco ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Muscle ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Respiratory Muscle Fatigue ◽  
Mitochondrial Ros ◽  
Transport Chain ◽  
Generating Capacity ◽  
Ros Formation ◽  
Modulated Process

Contraction-induced respiratory muscle fatigue and sepsis-related reductions in respiratory muscle force-generating capacity are mediated, at least in part, by reactive oxygen species (ROS). The subcellular sources and mechanisms of generation of ROS in these conditions are incompletely understood. We postulated that the physiological changes associated with muscle contraction (i.e., increases in calcium and ADP concentration) stimulate mitochondrial generation of ROS by a phospholipase A2(PLA2)-modulated process and that sepsis enhances muscle generation of ROS by upregulating PLA2activity. To test these hypotheses, we examined H2O2generation by diaphragm mitochondria isolated from saline-treated control and endotoxin-treated septic animals in the presence and absence of calcium and ADP; we also assessed the effect of PLA2inhibitors on H2O2formation. We found that 1) calcium and ADP stimulated H2O2formation by diaphragm mitochondria from both control and septic animals; 2) mitochondria from septic animals demonstrated substantially higher H2O2formation than mitochondria from control animals under basal, calcium-stimulated, and ADP-stimulated conditions; and 3) inhibitors of 14-kDa PLA2blocked the enhanced H2O2generation in all conditions. We also found that administration of arachidonic acid (the principal metabolic product of PLA2activation) increased mitochondrial H2O2formation by interacting with complex I of the electron transport chain. These data suggest that diaphragm mitochondrial ROS formation during contraction and sepsis may be critically dependent on PLA2activation.

scholarly journals Reactive Oxygen Species in Macrophages: Sources and Targets

2021 ◽  
Vol 12 ◽  
Author(s):  
Marcella Canton ◽  
Ricardo Sánchez-Rodríguez ◽  
Iolanda Spera ◽  
Francisca C. Venegas ◽  
Maria Favia ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Signaling Networks ◽  
Oxygen Species ◽  
Cellular Processes ◽  
Pathological Conditions ◽  
Mitochondrial Ros ◽  
Ros Formation ◽  
Excessive Accumulation

Reactive oxygen species (ROS) are fundamental for macrophages to eliminate invasive microorganisms. However, as observed in nonphagocytic cells, ROS play essential roles in processes that are different from pathogen killing, as signal transduction, differentiation, and gene expression. The different outcomes of these events are likely to depend on the specific subcellular site of ROS formation, as well as the duration and extent of ROS production. While excessive accumulation of ROS has long been appreciated for its detrimental effects, there is now a deeper understanding of their roles as signaling molecules. This could explain the failure of the “all or none” pharmacologic approach with global antioxidants to treat several diseases. NADPH oxidase is the first source of ROS that has been identified in macrophages. However, growing evidence highlights mitochondria as a crucial site of ROS formation in these cells, mainly due to electron leakage of the respiratory chain or to enzymes, such as monoamine oxidases. Their role in redox signaling, together with their exact site of formation is only partially elucidated. Hence, it is essential to identify the specific intracellular sources of ROS and how they influence cellular processes in both physiological and pathological conditions to develop therapies targeting oxidative signaling networks. In this review, we will focus on the different sites of ROS formation in macrophages and how they impact on metabolic processes and inflammatory signaling, highlighting the role of mitochondrial as compared to non-mitochondrial ROS sources.

scholarly journals Mechanism of the Formation of Electronically Excited Species by Oxidative Metabolic Processes: Role of Reactive Oxygen Species

Biomolecules ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 258 ◽  
Author(s):  
Pavel Pospíšil ◽  
Ankush Prasad ◽  
Marek Rác
Keyword(s):  
Reactive Oxygen Species ◽  
Molecular Oxygen ◽  
Reactive Oxygen ◽  
High Energy ◽  
Oxygen Species ◽  
Human Beings ◽  
Metabolic Processes ◽  
Excited Species ◽  
Electronically Excited

It is well known that biological systems, such as microorganisms, plants, and animals, including human beings, form spontaneous electronically excited species through oxidative metabolic processes. Though the mechanism responsible for the formation of electronically excited species is still not clearly understood, several lines of evidence suggest that reactive oxygen species (ROS) are involved in the formation of electronically excited species. This review attempts to describe the role of ROS in the formation of electronically excited species during oxidative metabolic processes. Briefly, the oxidation of biomolecules, such as lipids, proteins, and nucleic acids by ROS initiates a cascade of reactions that leads to the formation of triplet excited carbonyls formed by the decomposition of cyclic (1,2-dioxetane) and linear (tetroxide) high-energy intermediates. When chromophores are in proximity to triplet excited carbonyls, the triplet-singlet and triplet-triplet energy transfers from triplet excited carbonyls to chromophores result in the formation of singlet and triplet excited chromophores, respectively. Alternatively, when molecular oxygen is present, the triplet-singlet energy transfer from triplet excited carbonyls to molecular oxygen initiates the formation of singlet oxygen. Understanding the mechanism of the formation of electronically excited species allows us to use electronically excited species as a marker for oxidative metabolic processes in cells.

scholarly journals Mitochondrial uncoupling does not decrease reactive oxygen species production after ischemia-reperfusion

2014 ◽  
Vol 307 (7) ◽  
pp. H996-H1004 ◽  
Author(s):  
Ricardo Quarrie ◽  
Daniel S. Lee ◽  
Levy Reyes ◽  
Warren Erdahl ◽  
Douglas R. Pfeiffer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Myocardial Dysfunction ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Sprague Dawley ◽  
Mitochondrial Uncoupling ◽  
Mitochondrial Ros ◽  
Ros Formation

Cardiac ischemia-reperfusion (IR) leads to myocardial dysfunction by increasing production of reactive oxygen species (ROS). Mitochondrial H+ leak decreases ROS formation; it has been postulated that increasing H+ leak may be a mechanism of decreasing ROS production after IR. Ischemic preconditioning (IPC) decreases ROS formation after IR, but the mechanism is unknown. We hypothesize that pharmacologically increasing mitochondrial H+ leak would decrease ROS production after IR. We further hypothesize that IPC would be associated with an increase in the rate of H+ leak. Isolated male Sprague-Dawley rat hearts were subjected to either control or IPC. Mitochondria were isolated at end equilibration, end ischemia, and end reperfusion. Mitochondrial membrane potential (mΔΨ) was measured using a tetraphenylphosphonium electrode. Mitochondrial uncoupling was achieved by adding increasing concentrations of FCCP. Mitochondrial ROS production was measured by fluorometry using Amplex-Red. Pyridine dinucleotide levels were measured using HPLC. Before IR, increasing H+ leak decreased mitochondrial ROS production. After IR, ROS production was not affected by increasing H+ leak. H+ leak increased at end ischemia in control mitochondria. IPC mitochondria showed no change in the rate of H+ leak throughout IR. NADPH levels decreased after IR in both IPC and control mitochondria while NADH increased. Pharmacologically, increasing H+ leak is not a method of decreasing ROS production after IR. Replenishing the NADPH pool may be a means of scavenging the excess ROS thereby attenuating oxidative damage after IR.

scholarly journals Temperature-dependence of mitochondrial function and production of reactive oxygen species in the intertidal mud clam Mya arenaria

2002 ◽  
Vol 205 (13) ◽  
pp. 1831-1841 ◽  
Author(s):  
D. Abele ◽  
K. Heise ◽  
H. O. Pörtner ◽  
S. Puntarulo
Keyword(s):  
Reactive Oxygen Species ◽  
Heat Stress ◽  
Heat Exposure ◽  
Reactive Oxygen ◽  
Mya Arenaria ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Ros Formation ◽  
Proton Leakage ◽  
Intertidal Population

SUMMARY Mitochondrial respiration, energetic coupling to phosphorylation and the production of reactive oxygen species (ROS) were studied in mitochondria isolated from the eurythermal bivalve Mya arenaria (Myoidea) from a low-shore intertidal population of the German Wadden Sea. Measurements were conducted both within the range of the habitat temperatures (5-15 °C) and when subjected to heat exposure at 20 °C and 25 °C. Experimental warming resulted in an increase in the rate of state 3 and state 4 respiration in isolated mitochondria. The highest respiratory coupling ratios (RCR) were found at 15 °C; at higher temperatures mitochondrial coupling decreased,and release of ROS doubled between 15 and 25 °C. ROS production was 2-3%of total oxygen consumption in state 3 (0.3-0.5 nmol ROS mg-1protein min-1) at the habitat temperature, reaching a maximum of 4.3 % of state 3 respiration and 7 % of oligomycin-induced state 4+respiration under heat stress. Thus, state 4 respiration, previously interpreted exclusively as a measure of proton leakage, included a significant contribution from ROS formation in this animal, especially under conditions of heat stress. Oxygen radical formation was directly dependent on temperature-controlled respiration rates in states 3 and 4 and inversely related to mitochondrial coupling (RCR+) in state 4. Mitochondrial ROS formation is therefore involved in cellular heat stress in this eurythermal marine ectotherm.

scholarly journals The mystery of reactive oxygen species derived from cell respiration.

2004 ◽  
Vol 51 (1) ◽  
pp. 223-229 ◽  
Author(s):  
Hans Nohl ◽  
Lars Gille ◽  
Katrin Staniek
Keyword(s):  
Reactive Oxygen Species ◽  
Mitochondrial Respiration ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Cell Respiration ◽  
Detection Systems ◽  
Isolated Mitochondria ◽  
Mitochondrial Ros ◽  
Ros Formation ◽  
Electron Carriers

Mitochondrial respiration is considered to provide reactive oxygen species (ROS) as byproduct of regular electron transfer. Objections were raised since results obtained with isolated mitochondria are commonly transferred to activities of mitochondria in the living cell. High electrogenic membrane potential was reported to trigger formation of mitochondrial ROS involving complex I and III. Suggested bioenergetic parameters, starting ROS formation, widely change with the isolation mode. ROS detection systems generally applied may be misleading due to possible interactions with membrane constituents or electron carriers. Avoiding these problems no conditions reported to transform mitochondrial respiration to a radical source were confirmed. However, changing the physical membrane state affected the highly susceptible interaction of the ubiquinol/bc(1) redox complex such that ROS formation became possible.

scholarly journals Short Overview of ROS as Cell Function Regulators and Their Implications in Therapy Concepts

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 793 ◽  
Author(s):  
Lidija Milkovic ◽  
Ana Cipak Gasparovic ◽  
Marina Cindric ◽  
Pierre-Alexis Mouthuy ◽  
Neven Zarkovic
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Function ◽  
Reactive Oxygen ◽  
Redox Signaling ◽  
Oxygen Species ◽  
Cellular Functions ◽  
Short Overview ◽  
Ros Formation

The importance of reactive oxygen species (ROS) has been gradually acknowledged over the last four decades. Initially perceived as unwanted products of detrimental oxidative stress, they have been upgraded since, and now ROS are also known to be essential for the regulation of physiological cellular functions through redox signaling. In the majority of cases, metabolic demands, along with other stimuli, are vital for ROS formation and their actions. In this review, we focus on the role of ROS in regulating cell functioning and communication among themselves. The relevance of ROS in therapy concepts is also addressed here.

scholarly journals Generation of Reactive Oxygen Species by Mitochondria

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 415
Author(s):  
Pablo Hernansanz-Agustín ◽  
José Antonio Enríquez
Keyword(s):  
Reactive Oxygen Species ◽  
Electron Transport ◽  
Electron Transport Chain ◽  
Molecular Level ◽  
Reactive Oxygen ◽  
Level Of Detail ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Transport Chain ◽  
Chemical Products

Reactive oxygen species (ROS) are series of chemical products originated from one or several electron reductions of oxygen. ROS are involved in physiology and disease and can also be both cause and consequence of many biological scenarios. Mitochondria are the main source of ROS in the cell and, particularly, the enzymes in the electron transport chain are the major contributors to this phenomenon. Here, we comprehensively review the modes by which ROS are produced by mitochondria at a molecular level of detail, discuss recent advances in the field involving signalling and disease, and the involvement of supercomplexes in these mechanisms. Given the importance of mitochondrial ROS, we also provide a schematic guide aimed to help in deciphering the mechanisms involved in their production in a variety of physiological and pathological settings.

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