Superoxide Anion Radical-Triggered Ca<sup>2+</sup>Release from Cardiac Sarcoplasmic Reticulum through Ryanodine Receptor Ca<sup>2+</sup>Channel

Kawakami, Midori; Okabe, Eiichiro

doi:10.1124/mol.53.3.497

Cited by 132 publications

(73 citation statements)

References 26 publications

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“…Oxidative stress also activates the RyR but promotes maximal channel activity in an unregulated manner, reducing the ability of NO to exert feedback regulation of SR calcium release (32,35,36). As we have shown in the NOS1 Ϫ/Ϫ mice, higher O 2…”

Section: Discussionmentioning

confidence: 62%

Neuronal nitric oxide synthase negatively regulates xanthine oxidoreductase inhibition of cardiac excitation-contraction coupling

Khan

Lee

Minhas

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

215

206

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Although interactions between superoxide (O 2•؊ ) and nitric oxide underlie many physiologic and pathophysiologic processes, regulation of this crosstalk at the enzymatic level is poorly understood. Here, we demonstrate that xanthine oxidoreductase (XOR), a prototypic superoxide O 2•؊ -producing enzyme, and neuronal nitric oxide synthase (NOS1) coimmunoprecipitate and colocalize in the sarcoplasmic reticulum of cardiac myocytes. Deficiency of NOS1 (but not endothelial NOS, NOS3) leads to profound increases in XOR-mediated O 2•؊ production, which in turn depresses myocardial excitation-contraction coupling in a manner reversible by XOR inhibition with allopurinol. These data demonstrate a unique interaction between a nitric oxide and an O 2•؊ -generating enzyme that accounts for crosstalk between these signaling pathways; these findings demonstrate a direct antioxidant mechanism for NOS1 and have pathophysiologic implications for the growing number of disease states in which increased XOR activity plays a role.

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Section: Discussionmentioning

confidence: 62%

Neuronal nitric oxide synthase negatively regulates xanthine oxidoreductase inhibition of cardiac excitation-contraction coupling

Khan

Lee

Minhas

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

215

206

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“…In vitro experiments indicate that oxidation/alkylation, S-nitrosylation (38,68), or S-glutathionylation (38,62) of RyR1 hyperreactive SH residues enhances channel activity, whereas reduction to their free sulfhydryl state has the opposite effect (67)(68)(69)(70)(71)(72). In particular, incubation of isolated SR vesicles with superoxide anion or H 2 O 2 promotes RyR activation (42,(73)(74)(75).…”

Section: Discussionmentioning

confidence: 99%

A Transverse Tubule NADPH Oxidase Activity Stimulates Calcium Release from Isolated Triads via Ryanodine Receptor Type 1 S -Glutathionylation

Hidalgo

Pecchi

Barrientos

et al. 2006

Journal of Biological Chemistry

171

147

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We report here the presence of an NADPH oxidase (NOX) activity both in intact and in isolated transverse tubules and in triads isolated from mammalian skeletal muscle, as established by immunochemical, enzymatic, and pharmacological criteria. Immunohistochemical determinations with NOX antibodies showed that the gp91 phox membrane subunit and the cytoplasmic regulatory p47 phox subunit co-localized in transverse tubules of adult mice fibers with the ␣ 1s subunit of dihydropyridine receptors. Western blot analysis revealed that isolated triads contained the integral membrane subunits gp91 phox and p22 phox , which were markedly enriched in isolated transverse tubules but absent from junctional sarcoplasmic reticulum vesicles. Isolated triads and transverse tubules, but not junctional sarcoplasmic reticulum, also contained varying amounts of the cytoplasmic NOX regulatory subunits p47 phox and p67 phox . NADPH or NADH elicited superoxide anion and hydrogen peroxide generation by isolated triads; both activities were inhibited by NOX inhibitors but not by rotenone. NADH diminished the total thiol content of triads by one-third; catalase or apocynin, a NOX inhibitor, prevented this effect. NADPH enhanced the activity of ryanodine receptor type 1 (RyR1) in triads, measured through [ 3 H]ryanodine binding and calcium release kinetics, and increased significantly RyR1 S-glutathionylation over basal levels. Preincubation with reducing agents or NOX inhibitors abolished the enhancement of RyR1 activity produced by NADPH and prevented NADPH-induced RyR1 S-glutathionylation. We propose that reactive oxygen species generated by the transverse tubule NOX activate via redox modification the neighboring RyR1 Ca 2؉ release channels. Possible implications of this putative mechanism for skeletal muscle function are discussed.The NADPH oxidases (NOX) 3 are flavoprotein enzymes that use NADPH as electron donor to mediate the univalent reduction of molecular oxygen to superoxide anion (1), a free radical that by spontaneous or enzymatically catalyzed dismutation is readily converted into H 2 O 2 . The phagocytic NOX isoform (NOX2) was first discovered as a pivotal component of the neutrophil respiratory burst (2, 3). The functional NOX2 enzyme is composed of two integral plasma membrane subunits, gp91 phox and p22phox , which make up cytochrome b 558 , plus three cytosolic regulatory subunits: p40 phox , p47 phox , and p67 phox (2, 4). A variety of tissues, including endothelial cells (5), smooth muscle cells (6), neurons (7-9), and astrocytes (7, 10), possess nonphagocytic NOX homologues (11,12). Several reports indicate that NOX2 and its homologues have a central role in the generation of reactive oxygen species (ROS) in response to diverse physiological extracellular stimuli (13-17). Moreover, membrane depolarization stimulates NOX activity in phagocytes (18) and endothelial cells (19,20). NOX stimulation is also apparent following agonist-induced stimulation of N-methyl-D-aspartate receptors in hippocampal neurons (21). Some N...

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“…Both low-oxygen conditions and the subsequent reoxygenation phase perturb normal function in cardiac myocytes. Hypoxia/reoxygenation (H/R) injury alters the activity of ionic transport systems by inhibiting K ϩ channels (38), voltage-dependent L-type Ca 2ϩ channels (10), Na ϩ /Ca 2ϩ exchanger (47), and sarcoplasmic reticulum Ca 2ϩ -ATPase pump (40), and by stimulating store-operated channels (32) and ryanodine receptors (22).…”

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confidence: 99%

T-type calcium channels are regulated by hypoxia/reoxygenation in ventricular myocytes

Pluteanu

Cribbs

2009

American Journal of Physiology-Heart and Circulatory Physiology

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Pluteanu F, Cribbs LL. T-type calcium channels are regulated by hypoxia/reoxygenation in ventricular myocytes. Am J Physiol Heart Circ Physiol 297: H1304 -H1313, 2009. First published August 7, 2009 doi:10.1152/ajpheart.00528.2009.-Low-voltageactivated calcium channels are reexpressed in ventricular myocytes in pathological conditions associated with hypoxic episodes, but a direct relation between oxidative stress and T-type channel function and regulation in cardiomyocytes has not been established. We aimed to investigate low-voltage-activated channel regulation under oxidative stress in neonatal rat ventricular myocytes. RT-PCR measurements of voltage-gated Ca 2ϩ (Cav)3.1 and Cav3.2 mRNA levels in oxidative stress were compared with whole cell patch-clamp recordings of T-type calcium current. The results indicate that hypoxia reduces T-type current density at Ϫ30 mV (the hallmark of this channel) based on the shift of the voltage dependence of activation to more depolarized values and downregulation of Ca v3.1 at the mRNA level. Upon reoxygenation, both Ca v3.1 mRNA levels and the voltage dependence of total T-type current are restored, although differently for activation and inactivation. Using Ni 2ϩ , we distinguished different effects of hypoxia/reoxygenation on the two current components. Long-term incubation in the presence of 100 M CoCl 2 reproduced the effects of hypoxia on T-type current activation and inactivation, indicating that the chemically induced oxidative state is sufficient to alter T-type calcium current activity, and that hypoxia-inducible factor-1␣ is involved in Ca v3.1 downregulation. Our results demonstrate that Ca v3.1 and Cav3.2 T-type calcium channels are differentially regulated by hypoxia/reoxygenation injury, and, therefore, they may serve different functions in the myocyte in response to hypoxic injury. low-voltage-activated calcium channel; oxidative stress; cardiomyocytes SINCE THE INITIAL BIOPHYSICAL (34) and molecular characterization (5, 27, 36) of low-voltage-activated T-type calcium currents in heart and neurons, these channels have been studied in various systems and pathological conditions. T-type currents are reexpressed in the adult hypertrophied ventricle and in postmyocardial infarction (18), in the monocrotaline model of pulmonary hypertension and heart failure (24, 44), and in vitro in adult ventricular myocytes exposed to 10% FBS (9) and endothelin-1 (19), relating the T-type current to the pathology rather than to normal physiological function of the myocytes. The mechanisms for regulation of the T-type channels are incompletely characterized, largely due to the lack of specific inhibitors and the presence of the more robust L-type and store-operated calcium channels, which make it difficult to isolate T-type Ca 2ϩ channel functions, such as secretion (29), excitation (52), or transcription regulation (4).

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Superoxide Anion Radical-Triggered Ca²⁺Release from Cardiac Sarcoplasmic Reticulum through Ryanodine Receptor Ca²⁺Channel

Cited by 132 publications

References 26 publications

Neuronal nitric oxide synthase negatively regulates xanthine oxidoreductase inhibition of cardiac excitation-contraction coupling

Neuronal nitric oxide synthase negatively regulates xanthine oxidoreductase inhibition of cardiac excitation-contraction coupling

A Transverse Tubule NADPH Oxidase Activity Stimulates Calcium Release from Isolated Triads via Ryanodine Receptor Type 1 S -Glutathionylation

T-type calcium channels are regulated by hypoxia/reoxygenation in ventricular myocytes

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Superoxide Anion Radical-Triggered Ca2+Release from Cardiac Sarcoplasmic Reticulum through Ryanodine Receptor Ca2+Channel

Cited by 132 publications

References 26 publications

Neuronal nitric oxide synthase negatively regulates xanthine oxidoreductase inhibition of cardiac excitation-contraction coupling

Neuronal nitric oxide synthase negatively regulates xanthine oxidoreductase inhibition of cardiac excitation-contraction coupling

A Transverse Tubule NADPH Oxidase Activity Stimulates Calcium Release from Isolated Triads via Ryanodine Receptor Type 1 S -Glutathionylation

T-type calcium channels are regulated by hypoxia/reoxygenation in ventricular myocytes

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Superoxide Anion Radical-Triggered Ca²⁺Release from Cardiac Sarcoplasmic Reticulum through Ryanodine Receptor Ca²⁺Channel