A targeted antioxidant reveals the importance of mitochondrial reactive oxygen species in the hypoxic signaling of HIF‐1α

Sanjuán-Pla, Alejandra; Cervera, Ana M.; Apostolova, Nadezda; Garcia-Bou, Remedios; Víctor, Víctor M.; Murphy, Michael P.; McCreath, Kenneth J.

doi:10.1016/j.febslet.2005.03.088

Cited by 123 publications

(100 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other studies suggested that cells with impaired mitochondrial function fail to stabilize HIFα under hypoxia, not because of defective ROS-generation, but because of intracellular O 2 re-distribution which leads to increased availability of O 2 as a substrate for the hydroxylation reaction [72,78]. Although these reports challenge a role for mitochondrial ROS in cellular O 2 sensing, they do not explain why antioxidants, including the recently described mitochondrially-targeted compound MitoQ, block hypoxic HIFα activity [79]. In addition, they do not explain why defects which specifically compromise Complex III function prevent hypoxic HIFα activity, while Complex IV defects, that impair cellular respiration and presumably O 2 distribution, leave the hypoxic response intact [28].…”

Section: Role Of Ros In Cellular O 2 Sensingmentioning

confidence: 95%

Reactive oxygen species and cellular oxygen sensing

Cash

Pan

Simon

2007

Free Radical Biology and Medicine

160

100

View full text Add to dashboard Cite

Many organisms activate adaptive transcriptional programs to help them cope with decreased oxygen levels, or hypoxia, in their environment. These responses are triggered by various oxygen sensing systems in bacteria, yeast and metazoans. In metazoans, the hypoxia inducible factors (HIFs) mediate the adaptive transcriptional response to hypoxia by upregulating genes involved in maintaining bioenergetic homeostasis. The HIFs in turn are regulated by HIF-specific prolyl hydroxlase activity, which is sensitive to cellular oxygen levels and other factors such as tricarboxylic acid cycle metabolites and reactive oxygen species (ROS). Establishing a role for ROS in cellular oxygen sensing has been challenging since ROS are intrinsically unstable and difficult to measure. However, recent advances in fluorescence energy transfer resonance (FRET)-based methods for measuring ROS are alleviating some of the previous difficulties associated with dyes and luminescent chemicals. In addition, new genetic models have demonstrated that functional mitochondrial electron transport and associated ROS production during hypoxia are required for HIF stabilization in mammalian cells. Current efforts are directed at how ROS mediate prolyl hydroxylase activity and hypoxic HIF stabilization. Progress in understanding this process has been enhanced by the development of the FRET-based ROS probe, an vivo prolyl hydroxylase reporter and various genetic models harboring mutations in components of the mitochondrial electron transport chain.

show abstract

Section: Role Of Ros In Cellular O 2 Sensingmentioning

confidence: 95%

Reactive oxygen species and cellular oxygen sensing

Cash

Pan

Simon

2007

Free Radical Biology and Medicine

160

100

View full text Add to dashboard Cite

show abstract

“…30 The active antioxidant form of MQ is the reduced ubiquinol form, which is regenerated by the electron transport chain, and selectively blocks mitochondrial oxidative damage by detoxifying ROS. 16,17 This and other mitochondrial-targeted antioxidants have been shown to protect this organelle from oxidative stress in isolated cells 32 and living tissues 20 in hypoxia, 26 apoptosis, 29 and cancer. 18 In our experiments, continuous pretreatment with GTN produced a substantial reduction in its vasorelaxant effects of GTN when administered acutely, but not in those of acute DETA-NO.…”

Section: Discussionmentioning

confidence: 99%

“…24 Quantitative assessment of hydrogen peroxide (H 2 O 2 ) was performed with the Amplex Red H 2 O 2 /Peroxidase Assay kit (Molecular Probes, Eugene, Ore). 25,26 GSH content was assessed following incubation (30 minutes) with the fluorescent probe monochlorobimane (MCB) (40ϫ10 Ϫ6 mol/L). GSH levels were also measured by confocal microscopy (Leica, Heidelberg, Germany), following incubation (30 minutes) with 5-chloromethylfluorescein diacetate (CMFDA) (1ϫ10 Ϫ6 mol/L).…”

Section: Measurement Of Ros Production Gsh Content and Complex I Acmentioning

confidence: 99%

Complex I Dysfunction and Tolerance to Nitroglycerin

Esplugues

Rocha

Núñez

et al. 2006

Circulation Research

View full text Add to dashboard Cite

Abstract-Nitroglycerin (GTN) tolerance was induced in vivo (rats) and in vitro (rat and human vessels). Electrochemical detection revealed that the incubation dose of GTN (5ϫ10 Ϫ6 mol/L) did not release NO or modify O 2 consumption when administered acutely. However, development of tolerance produced a decrease in both mitochondrial O 2 consumption and the K m for O 2 in animal and human vessels and endothelial cells in a noncompetitive action. GTN tolerance has been associated with impairment of GTN biotransformation through inhibition of aldehyde dehydrogenase (ALDH)-2, and with uncoupling of mitochondrial respiration. Feeding rats with mitochondrial-targeted antioxidants (mitoquinone [MQ]) and in vitro coincubation with MQ (10 Ϫ6 mol/L) or glutathione (GSH) ester (10 Ϫ4 mol/L) prevented tolerance and the effects of GTN on mitochondrial respiration and ALDH-2 activity. Biotransformation of GTN requires functionally active mitochondria and induces reactive oxygen species production and oxidative stress within this organelle, as it is inhibited by mitochondrial-targeted antioxidants and is absent in HUVEC 0 cells. Experiments analyzing complex I-dependent respiration demonstrate that its inhibition by GTN is prevented by mitochondrial-targeted antioxidants. Furthermore, in presence of succinate (10ϫ10 Ϫ3 mol/L), a complex II electron donor added to bypass complex I-dependent respiration, GTN-treated cells exhibited O 2 consumption rates similar to those of controls, thus suggesting that complex I was affected by GTN. We propose that, following prolonged treatment with GTN in addition to ALDH-2, complex I is a target for mitochondrially generated reactive oxygen species. Our data also suggest a role for mitochondrial-targeted antioxidants as therapeutic tools in the control of the tolerance that accompanies chronic nitrate use. ) have generally been attributed to its bioconversion into the relaxant agent nitric oxide (NO), which acts on the enzyme soluble guanylate cyclase (sGC). [1][2][3] However, most studies that support the existence of such a pathway have demonstrated increases of NO only when GTN concentrations considerably exceeded the plasma levels reached during clinical dosing. 4 Moreover, the involvement of other NO-related species in the actions of GTN when used at clinically relevant concentrations is also under debate. 5,6 Different enzymes have been implicated in the bioconversion of GTN, in particular, glutathione S-transferases, 7 the cytochrome p450 system, 8 and xanthine oxidoreductase, 9 although the most recent evidence suggests a central role for mitochondrial aldehyde dehydrogenase (ALDH)-2. 10 -13 The medical use of GTN is limited by the development of tolerance, which occurs following prolonged administration or the application of high doses. This phenomenon has been related to various mechanisms, in particular, desensitization of sGC, 14 and, mainly, impairment of GTN biotransformation by inhibition of ALDH-2. 10 -12 These actions, like others associated with GTN, have been linked to a...

show abstract

“…Preparation of total protein extracts, membrane transfer and detection were carried out as described [22]. Primary antibodies for immunoblot were purchased as follows: Phospo-p38 and p38 from Cell Signaling (Danvers, MA, http://www.cellsignal.com), tubulin and actin from Sigma-Aldrich, and cardiac troponin I from Abcam (Abcam, plc., Cambridge, U.K., http://www.abcam.com).…”

Section: Immunoblotting and Immunocytochemistrymentioning

confidence: 99%

“…Endogenous respiration in whole cells was measured with a Clark-type oxygen electrode (Rank Bros., Bottisham, U.K., http:// www.rankbrothers.co.uk), as described in [22].…”

Section: Cellular Respirationmentioning

confidence: 99%

Mitochondrial Reactive Oxygen Species Mediate Cardiomyocyte Formation from Embryonic Stem Cells in High Glucose

et al. 2010

Self Cite

View full text Add to dashboard Cite

Accumulating evidence points to reactive oxygen species (ROS) as important signaling molecules for cardiomyocyte differentiation in embryonic stem (ES) cells. Given that ES cells are normally maintained and differentiated in medium containing supraphysiological levels of glucose (25 mM), a condition which is known to result in enhanced cellular ROS formation, we questioned whether this high glucose concentration was necessary for cardiomyocyte lineage potential. We show here that ES cells cultured in physiological glucose (5 mM), maintained their general stemness qualities but displayed an altered mitochondrial metabolism, which resulted in decreased ROS production. Furthermore, ES and induced pluripotent stem (iPS) cells differentiated in lower glucose concentrations failed to generate cardiomyocyte structures; an effect mimicked with antioxidant treatments using catalase, N-acetyl cysteine and mitoubiquinone, under high glucose conditions in ES cells. Molecular analysis revealed that ES cells differentiated in 5 mM glucose had reduced expression of the pro-cardiac NOX4 gene and diminished phosphorylation of p38 mitogen-activated protein kinase (MAPK), together with specific changes in the cardiac transcriptional network. These outcomes could be reversed by supplementation of low glucose cultures with ascorbic acid, paradoxically acting as a pro-oxidant. Furthermore, forced expression of an upstream p38 MAPK kinase (MKK6) could bypass the requirement for ROS during differentiation to cardiomyocytes under low glucose conditions, illustrating a key role for p38 in the cardiac differentiation program. Together these data demonstrate that endogenous ROS control is important for cardiomyocyte formation from ES cells, and furthermore that supraphysiological glucose, by supplying ROS, is absolutely required.

show abstract

A targeted antioxidant reveals the importance of mitochondrial reactive oxygen species in the hypoxic signaling of HIF‐1α

Cited by 123 publications

References 44 publications

Reactive oxygen species and cellular oxygen sensing

Reactive oxygen species and cellular oxygen sensing

Complex I Dysfunction and Tolerance to Nitroglycerin

Mitochondrial Reactive Oxygen Species Mediate Cardiomyocyte Formation from Embryonic Stem Cells in High Glucose

Contact Info

Product

Resources

About