scholarly journals Reactive Oxygen Species (ROS) Play a Critical Role in the cAMP-Induced Activation of Ras and the Phosphorylation of ERK1/2 in Leydig Cells

2011 ◽  
Vol 25 (5) ◽  
pp. 885-893 ◽  
Author(s):  
Ping Tai ◽  
Mario Ascoli
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Leydig Cells ◽  
Critical Role ◽  
Primary Cultures ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Mitochondrial Ros ◽  
Mitochondrial Functions ◽  
Ros Scavenger

Abstract Activation of the LH receptor (LHR) in Leydig cells results in the phosphorylation of ERK1/2 by cAMP-dependent and cAMP-independent pathways. Here we examine the mechanisms by which cAMP stimulates ERK1/2 phosphorylation. We show that the stimulation of steroidogenesis is not necessary or sufficient to stimulate the phosphorylation of ERK1/2 but that other cAMP-dependent mitochondrial functions are involved. Using MA-10 cells as a model, we showed that cAMP analogs increase reactive oxygen species (ROS) formation and that an uncoupler of oxidative phosphorylation and a ROS scavenger prevent this increase. These two compounds also inhibit the increase in ERK1/2 phosphorylation provoked by cAMP analogs, thus suggesting that the cAMP-induced phosphorylation of ERK1/2 is mediated by mitochondrial ROS. In agreement with this hypothesis we also show that a reduction in glutathione levels, which alters the redox state of MA-10 cells, potentiates the effect of cAMP on ERK1/2 phosphorylation. Measurements of the dephosphorylation of ERK and the activation of Ras showed that the ROS scavenger prevents the cAMP-provoked activation of Ras and that cAMP, with or without a ROS scavenger, has little or no effect on the dephosphorylation of ERK. Lastly, we show that the uncoupler of oxidative phosphorylation and the ROS scavenger also prevent the ability of cAMP analogs to increase ERK1/2 phosphorylation in primary cultures of mouse Leydig cells. We conclude that, in Leydig cells, cAMP enhances the phosphorylation of ERK1/2 via a mitochondria-derived, ROS-dependent activation of Ras.

Mitochondrial-derived reactive oxygen species influence ADP sensitivity, but not CPT-I substrate sensitivity

2018 ◽  
Vol 475 (18) ◽  
pp. 2997-3008 ◽  
Author(s):  
Pierre-Andre Barbeau ◽  
Paula M. Miotto ◽  
Graham P. Holloway
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Acute Exercise ◽  
Adenine Nucleotide ◽  
Mitochondrial Protein ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Emission Rates ◽  
Mitochondrial Ros ◽  
Cpt I

The mechanisms regulating oxidative phosphorylation during exercise remain poorly defined; however, key mitochondrial proteins, including carnitine palmitoyltransferase-I (CPT-I) and adenine nucleotide translocase, have redox-sensitive sites. Interestingly, muscle contraction has recently been shown to increase mitochondrial membrane potential and reactive oxygen species (ROS) production; therefore, we aimed to determine if mitochondrial-derived ROS influences bioenergetic responses to exercise. Specifically, we examined the influence of acute exercise on mitochondrial bioenergetics in WT (wild type) and transgenic mice (MCAT, mitochondrial-targeted catalase transgenic) possessing attenuated mitochondrial ROS. We found that ablating mitochondrial ROS did not alter palmitoyl-CoA (P-CoA) respiratory kinetics or influence the exercise-mediated reductions in malonyl CoA sensitivity, suggesting that mitochondrial ROS does not regulate CPT-I. In contrast, while mitochondrial protein content, maximal coupled respiration, and ADP (adenosine diphosphate) sensitivity in resting muscle were unchanged in the absence of mitochondrial ROS, exercise increased the apparent ADP Km (decreased ADP sensitivity) ∼30% only in WT mice. Moreover, while the presence of P-CoA decreased ADP sensitivity, it did not influence the basic response to exercise, as the apparent ADP Km was increased only in the presence of mitochondrial ROS. This basic pattern was also mirrored in the ability of ADP to suppress mitochondrial H2O2 emission rates, as exercise decreased the suppression of H2O2 only in WT mice. Altogether, these data demonstrate that while exercise-induced mitochondrial-derived ROS does not influence CPT-I substrate sensitivity, it inhibits ADP sensitivity independent of P-CoA. These data implicate mitochondrial redox signaling as a regulator of oxidative phosphorylation.

scholarly journals Modulations of Cardiac Functions and Pathogenesis by Reactive Oxygen Species and Natural Antioxidants

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 760
Author(s):  
Sun-Hee Woo ◽  
Joon-Chul Kim ◽  
Nipa Eslenur ◽  
Tran-Nguyet Trinh ◽  
Long Nguyen Hoàng Do
Keyword(s):  
Reactive Oxygen Species ◽  
Cardiac Myocytes ◽  
Cardiac Myocyte ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Natural Antioxidants ◽  
Oxygen Species ◽  
Membrane Conductivity ◽  
Cardiac Functions ◽  
Mitochondrial Functions

Homeostasis in the level of reactive oxygen species (ROS) in cardiac myocytes plays a critical role in regulating their physiological functions. Disturbance of balance between generation and removal of ROS is a major cause of cardiac myocyte remodeling, dysfunction, and failure. Cardiac myocytes possess several ROS-producing pathways, such as mitochondrial electron transport chain, NADPH oxidases, and nitric oxide synthases, and have endogenous antioxidation mechanisms. Cardiac Ca2+-signaling toolkit proteins, as well as mitochondrial functions, are largely modulated by ROS under physiological and pathological conditions, thereby producing alterations in contraction, membrane conductivity, cell metabolism and cell growth and death. Mechanical stresses under hypertension, post-myocardial infarction, heart failure, and valve diseases are the main causes for stress-induced cardiac remodeling and functional failure, which are associated with ROS-induced pathogenesis. Experimental evidence demonstrates that many cardioprotective natural antioxidants, enriched in foods or herbs, exert beneficial effects on cardiac functions (Ca2+ signal, contractility and rhythm), myocytes remodeling, inflammation and death in pathological hearts. The review may provide knowledge and insight into the modulation of cardiac pathogenesis by ROS and natural antioxidants.

scholarly journals Reactive Oxygen Species: Beyond Their Reactive Behavior

2021 ◽  
Vol 46 (1) ◽  
pp. 77-87
Author(s):  
Arnaud Tauffenberger ◽  
Pierre J. Magistretti
Keyword(s):  
Reactive Oxygen Species ◽  
Second Messengers ◽  
Critical Role ◽  
Complex Function ◽  
Reactive Oxygen ◽  
High Reactivity ◽  
Oxygen Species ◽  
Health And Disease ◽  
Cellular Dysfunction ◽  
The Brain

AbstractCellular homeostasis plays a critical role in how an organism will develop and age. Disruption of this fragile equilibrium is often associated with health degradation and ultimately, death. Reactive oxygen species (ROS) have been closely associated with health decline and neurological disorders, such as Alzheimer’s disease or Parkinson’s disease. ROS were first identified as by-products of the cellular activity, mainly mitochondrial respiration, and their high reactivity is linked to a disruption of macromolecules such as proteins, lipids and DNA. More recent research suggests more complex function of ROS, reaching far beyond the cellular dysfunction. ROS are active actors in most of the signaling cascades involved in cell development, proliferation and survival, constituting important second messengers. In the brain, their impact on neurons and astrocytes has been associated with synaptic plasticity and neuron survival. This review provides an overview of ROS function in cell signaling in the context of aging and degeneration in the brain and guarding the fragile balance between health and disease.

scholarly journals Tomato SlIDA has a critical role in tomato fertilization by modifying reactive oxygen species homeostasis

2020 ◽  
Vol 103 (6) ◽  
pp. 2100-2118
Author(s):  
Rong Wang ◽  
ChunLin Shi ◽  
Xiaoyang Wang ◽  
Ruizhen Li ◽  
Yan Meng ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Oxygen Species

scholarly journals Protein Kinase D Mediates Mitochondrion-to-Nucleus Signaling and Detoxification from Mitochondrial Reactive Oxygen Species

2005 ◽  
Vol 25 (19) ◽  
pp. 8520-8530 ◽  
Author(s):  
Peter Storz ◽  
Heike Döppler ◽  
Alex Toker
Keyword(s):  
Reactive Oxygen Species ◽  
Transcription Factor ◽  
Protein Kinase ◽  
Reactive Oxygen ◽  
Protein Kinase D ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Mitochondrial Oxidative Stress ◽  
Cellular Survival ◽  
Mitochondrial Ros

ABSTRACT Efficient elimination of mitochondrial reactive oxygen species (mROS) correlates with increased cellular survival and organism life span. Detoxification of mitochondrial ROS is regulated by induction of the nuclear SOD2 gene, which encodes the manganese-dependent superoxide dismutase (MnSOD). However, the mechanisms by which mitochondrial oxidative stress activates cellular signaling pathways leading to induction of nuclear genes are not known. Here we demonstrate that release of mROS activates a signal relay pathway in which the serine/threonine protein kinase D (PKD) activates the NF-κB transcription factor, leading to induction of SOD2. Conversely, the FOXO3a transcription factor is dispensable for mROS-induced SOD2 induction. PKD-mediated MnSOD expression promotes increased survival of cells upon release of mROS, suggesting that mitochondrion-to-nucleus signaling is necessary for efficient detoxification mechanisms and cellular viability.

scholarly journals Mechanisms of Mitochondrial Damage in Keratinocytes by Pemphigus Vulgaris Antibodies

2013 ◽  
Vol 288 (23) ◽  
pp. 16916-16925 ◽  
Author(s):  
Mina Kalantari-Dehaghi ◽  
Yumay Chen ◽  
Wu Deng ◽  
Alex Chernyavsky ◽  
Steve Marchenko ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Mouse Skin ◽  
Reactive Oxygen ◽  
Pemphigus Vulgaris ◽  
Mitochondrial Damage ◽  
Response To Treatment ◽  
Transfer Model ◽  
Clear Understanding ◽  
Oxygen Species ◽  
Mitochondrial Functions

The development of nonhormonal treatment of pemphigus vulgaris (PV) has been hampered by a lack of clear understanding of the mechanisms leading to keratinocyte (KC) detachment and death in pemphigus. In this study, we sought to identify changes in the vital mitochondrial functions in KCs treated with the sera from PV patients and healthy donors. PV sera significantly increased proton leakage from KCs, suggesting that PV IgGs increase production of reactive oxygen species. Indeed, measurement of intracellular reactive oxygen species production showed a drastic increase of cell staining in response to treatment by PV sera, which was confirmed by FACS analysis. Exposure of KCs to PV sera also caused dramatic changes in the mitochondrial membrane potential detected with the JC-1 dye. These changes can trigger the mitochondria-mediated intrinsic apoptosis. Although sera from different PV patients elicited unique patterns of mitochondrial damage, the mitochondria-protecting drugs nicotinamide (also called niacinamide), minocycline, and cyclosporine A exhibited a uniform protective effect. Their therapeutic activity was validated in the passive transfer model of PV in neonatal BALB/c mice. The highest efficacy of mitochondrial protection of the combination of these drugs found in mitochondrial assay was consistent with the ability of the same drug combination to abolish acantholysis in mouse skin. These findings provide a theoretical background for clinical reports of the efficacy of mitochondria-protecting drugs in PV patients. Pharmacological protection of mitochondria and/or compensation of an altered mitochondrial function may therefore become a novel approach to development of personalized nonhormonal therapies of patients with this potentially lethal autoimmune blistering disease.

Sign in / Sign up

Export Citation Format

Share Document