Hypoxia activates NADPH oxidase to increase [ROS]i and [Ca2+]i through the mitochondrial ROS-PKCɛ signaling axis in pulmonary artery smooth muscle cells

Rathore, Rakesh; Zheng, Yun Min; Niu, Chun Feng; Liu, Qing Hua; Korde, Amit S.; Ho, Ye Shih; Wang, Yong Xiao

doi:10.1016/j.freeradbiomed.2008.06.012

Cited by 252 publications

(261 citation statements)

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“…since its depletion impairs cardiomyocyte differentiation [18]. Given that NADH oxidases can be activated by mitochondrial ROS [35], we determined whether NOX4 expression is a causal factor in ES cell-responses to high glucose. We first used R19 ES cells containing an integrated ribozyme against NOX4 [18], and quantified beating foci during EB differentiation.…”

Section: Resultsmentioning

confidence: 99%

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

et al. 2010

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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.

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Section: Resultsmentioning

confidence: 99%

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

et al. 2010

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“…The blockade of hypoxia-induced ROS responses we observe with depletion of RISP suggests that the mitochondria may act as the initiators of ROS production, which could be amplified by engagement of nonphagocytic nicotinamide adenine dinucleotide phosphate reduced oxidase systems elsewhere in the cell. Such "ROS-induced ROS release" might permit small ROS signals generated by mitochondria to activate ROS signaling throughout the cell, thereby avoiding mitochondrial damage that might arise if the entire cellular oxidant signal originated from that organelle (15). Regardless of the source, ROS signals trigger diverse functional responses to hypoxia in PASMC, including calcium signaling and AMP-regulated kinase (AMPK) activation (12, 41).…”

Section: Discussionmentioning

confidence: 99%

“…Our previous work has implicated increases in reactive oxygen species (ROS) signaling during hypoxia (9,10,12). Previous studies using mitochondrial inhibitors and mitochondria-deficient (r 0 ) cells suggested that the electron transport chain (ETC) is required for hypoxia-induced ROS signaling in the pulmonary circulation (9,(11)(12)(13)(14)(15)(16)(17)(18). We subsequently assessed ROS signaling in hypoxic PASMC using roGFP, a thiol-containing, redox-sensitive reporter (19)(20)(21)(22)(23) targeted to compartments within mitochondria or the cytosol (10).…”

mentioning

confidence: 99%

Superoxide Generated at Mitochondrial Complex III Triggers Acute Responses to Hypoxia in the Pulmonary Circulation

Waypa

Marks

Guzy

et al. 2013

Am J Respir Crit Care Med

133

145

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Rationale: The role of reactive oxygen species (ROS) signaling in the O 2 sensing mechanism underlying acute hypoxic pulmonary vasoconstriction (HPV) has been controversial. Although mitochondria are important sources of ROS, studies using chemical inhibitors have yielded conflicting results, whereas cellular models using genetic suppression have precluded in vivo confirmation. Hence, genetic animal models are required to test mechanistic hypotheses. Objectives: We tested whether mitochondrial Complex III is required for the ROS signaling and vasoconstriction responses to acute hypoxia in pulmonary arteries (PA). Methods: A mouse permitting Cre-mediated conditional deletion of the Rieske iron-sulfur protein (RISP) of Complex III was generated. Adenoviral Cre recombinase was used to delete RISP from isolated PA vessels or smooth muscle cells (PASMC). Measurements and Main Results: In PASMC, RISP depletion abolished hypoxia-induced increases in ROS signaling in the mitochondrial intermembrane space and cytosol, and it abrogated hypoxia-induced increases in [Ca 21 ] i . In isolated PA vessels, RISP depletion abolished hypoxia-induced ROS signaling in the cytosol. Breeding the RISP mice with transgenic mice expressing tamoxifen-activated Cre in smooth muscle permitted the depletion of RISP in PASMC in vivo. Precision-cut lung slices from those mice revealed that RISP depletion abolished hypoxia-induced increases in [Ca 21 ] i of the PA. In vivo RISP depletion in smooth muscle attenuated the acute hypoxia-induced increase in right ventricular systolic pressure in anesthetized mice. Conclusions: Acute hypoxia induces superoxide release from Complex III of smooth muscle cells. These oxidant signals diffuse into the cytosol and trigger increases in [Ca 21 ] i that cause acute hypoxic pulmonary vasoconstriction.Keywords: oxygen sensing; Rieske iron-sulfur protein; reactive oxygen species; roGFP; hypoxic pulmonary vasoconstrictionIn the lung, alveolar hypoxia triggers acute constriction of small pulmonary arteries (PA), a response termed hypoxic pulmonary vasoconstriction (HPV). This response is recapitulated in cultured PA smooth muscle cells (PASMC), indicating that the oxygen-sensing mechanism underlying HPV is intrinsic to the PASMC (1-12). Our previous work has implicated increases in reactive oxygen species (ROS) signaling during hypoxia (9,10, 12). Previous studies using mitochondrial inhibitors and mitochondria-deficient (r 0 ) cells suggested that the electron transport chain (ETC) is required for hypoxia-induced ROS signaling in the pulmonary circulation (9, 11-18). We subsequently assessed ROS signaling in hypoxic PASMC using roGFP, a thiol-containing, redox-sensitive reporter (19-23) targeted to compartments within mitochondria or the cytosol (10). Unlike other methods (24-26), this targeted approach permitted the differentiation of hypoxia-induced ROS changes between mitochondrial subcompartments. During hypoxia, increased oxidation was detected in the mitochondrial intermembrane space (IMS) and the cytoso...

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“…Induction of Nox1 by Ang II may involve mitochondria, possibly through a Ca 2 + -dependent mechanism (163). Nox1 is also activated by H 2 O 2 in VSMCs.…”

Section: Nox1mentioning

confidence: 99%

Reactive Oxygen Species, Vascular Noxs, and Hypertension: Focus on Translational and Clinical Research

Montezano

Touyz²

2014

Antioxidants & Redox Signaling

229

177

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Significance: Reactive oxygen species (ROS) are signaling molecules that are important in physiological processes, including host defense, aging, and cellular homeostasis. Increased ROS bioavailability and altered redox signaling (oxidative stress) have been implicated in the onset and/or progression of chronic diseases, including hypertension. Recent Advances: Although oxidative stress may not be the only cause of hypertension, it amplifies blood pressure elevation in the presence of other pro-hypertensive factors, such as salt loading, activation of the renin-angiotensin-aldosterone system, and sympathetic hyperactivity, at least in experimental models. A major source for ROS in the cardiovascular-renal system is a family of nicotinamide adenine dinucleotide phosphate oxidases (Noxs), including the prototypic Nox2-based Nox, and Nox family members: Nox1, Nox4, and Nox5. Critical Issues: Although extensive experimental data support a role for increased ROS levels and altered redox signaling in the pathogenesis of hypertension, the role in clinical hypertension is unclear, as a direct causative role of ROS in blood pressure elevation has yet to be demonstrated in humans. Nevertheless, what is becoming increasingly evident is that abnormal ROS regulation and aberrant signaling through redoxsensitive pathways are important in the pathophysiological processes which is associated with vascular injury and target-organ damage in hypertension. Future Directions: There is a paucity of clinical information related to the mechanisms of oxidative stress and blood pressure elevation, and a few assays accurately measure ROS directly in patients. Such further ROS research is needed in humans and in the development of adequately validated analytical methods to accurately assess oxidative stress in the clinic. Antioxid. Redox Signal. 20,[164][165][166][167][168][169][170][171][172][173][174][175][176][177][178][179][180][181][182]

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Hypoxia activates NADPH oxidase to increase [ROS]i and [Ca2+]i through the mitochondrial ROS-PKCɛ signaling axis in pulmonary artery smooth muscle cells

Cited by 252 publications

References 57 publications

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

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

Superoxide Generated at Mitochondrial Complex III Triggers Acute Responses to Hypoxia in the Pulmonary Circulation

Reactive Oxygen Species, Vascular Noxs, and Hypertension: Focus on Translational and Clinical Research

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