Na+–Ca2+ exchanger overexpression predisposes to reactive oxygen species-induced injury

Wagner, Stefan; Seidler, Tim; Picht, Eckard; Maier, Lars S.; Kazanski, Victor; Teucher, Nils; Schillinger, Wolfgang; Pieske, Burkert; Isenberg, Gerrit; Hasenfuß, Gerd; Kögler, Harald

doi:10.1016/j.cardiores.2003.08.006

Cited by 46 publications

(34 citation statements)

References 39 publications

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“…We also tested the possibility that the isolation procedure might lead to oxidation and loss of NO sensitivity of NO-GC. Even when all isolation steps and measurements were performed in the presence of the reactive oxygen species scavenger melatonin (100 μmol/L), 41 no response to NO donors could be attained. In addition, the direct NO-GC activator BAY-58-2667 (cinaciguat) capable of activating even oxidized NO-GC 42 did not show any response (Online Figure I), suggesting that cardiomyocyte isolation per se is unlikely to inactivate NO-GC.…”

Section: Discussionmentioning

confidence: 99%

Transgenic Mice for Real-Time Visualization of cGMP in Intact Adult Cardiomyocytes

Götz

Sprenger

Perera³

et al. 2014

Circulation Research

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1235 3ʹ,5ʹ-Cyclic guanosine monophosphate (cGMP) is one of the ubiquitous second messengers, which is critically involved in the regulation of cardiac contractility and pathological hypertrophy.1,2 In cardiomyocytes, 2 classes of guanylyl cyclases (GCs) are responsible for cGMP synthesis. The first class, particulate GCs (pGCs) represented by GC-A and GC-B, are plasma membrane receptors for atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP), respectively. 3,4 Second, the so-called soluble or NO-sensitive GCs (NO-GCs) are also functionally present in cardiomyocytes.5-7 cGMP levels are negatively regulated by cGMP-hydrolyzing enzymes phosphodiesterases (PDEs) with at least 4 families (PDE1, 2, 3, and 5) expressed in cardiac myocytes, whereby the first 3 PDEs can degrade both cGMP and cAMP. [8][9][10][11] cGMP is generally considered as a cardioprotective second messenger, 12 because pharmacological elevation of cGMP levels either by inhibition of cGMP-hydrolyzing PDE5 and PDE1 or by activation of NO-GC and pGC prevents pathological cardiomyocyte growth in vitro 13 and cardiac remodeling in vivo. 2,14-16In This Issue, see p 1221Reliable cGMP measurements in adult cardiomyocytes have been challenging. 17 In adult heart, cGMP is present at much lower concentrations than cAMP and acts in a compartmentalized New Methods in Cardiovascular Biology© 2014 American Heart Association, Inc. Rationale: 3ʹ,5ʹ-Cyclic guanosine monophosphate (cGMP) is an important second messenger that regulates cardiac contractility and protects the heart from hypertrophy. However, because of the lack of real-time imaging techniques, specific subcellular mechanisms and spatiotemporal dynamics of cGMP in adult cardiomyocytes are not well understood.Objective: Our aim was to generate and characterize a novel cGMP sensor model to measure cGMP with nanomolar sensitivity in adult cardiomyocytes. Methods and Results:We generated transgenic mice with cardiomyocyte-specific expression of the highly sensitive cytosolic Förster resonance energy transfer-based cGMP biosensor red cGES-DE5 and performed the first Förster resonance energy transfer measurements of cGMP in intact adult mouse ventricular myocytes. We found very low (≈10 nmol/L) basal cytosolic cGMP levels, which can be markedly increased by natriuretic peptides (C-type natriuretic peptide >> atrial natriuretic peptide) and, to a much smaller extent, by the direct stimulation of soluble guanylyl cyclase. Constitutive activity of this cyclase contributes to basal cGMP production, which is balanced by the activity of clinically established phosphodiesterase (PDE) families. The PDE3 inhibitor, cilostamide, showed especially strong cGMP responses. In a mild model of cardiac hypertrophy after transverse aortic constriction, PDE3 effects were not affected, whereas the contribution of PDE5 was increased. In addition, after natriuretic peptide stimulation, PDE3 was also involved in cGMP/cAMP crosstalk. Conclusions:

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Section: Discussionmentioning

confidence: 99%

Transgenic Mice for Real-Time Visualization of cGMP in Intact Adult Cardiomyocytes

Götz

Sprenger

Perera³

et al. 2014

Circulation Research

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“…Ventricular myocytes were isolated from rabbits and plated on culture dishes (36). Transfection with recombinant adenovirus encoding for HA-tagged CaMKIIδC (or β-gal as control) was performed at an MOI of 100 during plating of rabbit myocytes in supplemented M199 culture medium for 24 hours (34,37).…”

Section: Methodsmentioning

confidence: 99%

“…[Na]i. Myocytes were loaded with 10 μM sodium-binding benzofuran isophthalate-AM (SBFI-AM; Invitrogen) for 2 hours at room temperature (36,38), mounted on the microscope stage, and superfused with Tyrode solution (in mM): 140 NaCl, 4 KCl, 1 MgCl2, 5 HEPES, 10 glucose, 1 (mouse) or 2 (rabbit) CaCl2 (pH 7.4, 37°C). Myocytes were paced at various stimulation frequencies using field stimulation (10-20 V).…”

Section: Patch-clamp Experiments Ruptured-patch Whole-cell Voltage-cmentioning

confidence: 99%

Ca2+/calmodulin-dependent protein kinase II regulates cardiac Na+ channels

et al. 2006

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In heart failure (HF), Ca 2+ /calmodulin kinase II (CaMKII) expression is increased. Altered Na + channel gating is linked to and may promote ventricular tachyarrhythmias (VTs) in HF. Calmodulin regulates Na + channel gating, in part perhaps via CaMKII. We investigated effects of adenovirus-mediated (acute) and Tg (chronic) overexpression of cytosolic CaMKIIδ C on Na + current (I Na ) in rabbit and mouse ventricular myocytes, respectively (in whole-cell patch clamp). Both acute and chronic CaMKIIδ C overexpression shifted voltage dependence of Na + channel availability by -6 mV (P < 0.05), and the shift was Ca 2+ dependent. CaMKII also enhanced intermediate inactivation and slowed recovery from inactivation (prevented by CaMKII inhibitors autocamtide 2-related inhibitory peptide [AIP] or KN93). CaMKIIδ C markedly increased persistent (late) inward I Na and intracellular Na + concentration (as measured by the Na + indicator sodium-binding benzofuran isophthalate [SBFI]), which was prevented by CaMKII inhibition in the case of acute CaMKIIδ C overexpression. CaMKII coimmunoprecipitates with and phosphorylates Na + channels. In vivo, transgenic CaMKIIδ C overexpression prolonged QRS duration and repolarization (QT intervals), decreased effective refractory periods, and increased the propensity to develop VT. We conclude that CaMKII associates with and phosphorylates cardiac Na + channels. This alters I Na gating to reduce availability at high heart rate, while enhancing late I Na (which could prolong action potential duration). In mice, enhanced CaMKIIδ C activity predisposed to VT. Thus, CaMKIIdependent regulation of Na + channel function may contribute to arrhythmogenesis in HF.

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“…Several reports have suggested that ROS induces intracellular Ca 2ϩ overload through activation of a reversed mode of Na ϩ -Ca 2ϩ exchange during reoxygenation. 22,23 Therefore, we examined the effect of the specific inhibitor of Na ϩ -Ca 2ϩ exchange, SEA0400, 24 on normal myocyte function. SEA0400 (1 mol/L) had no appreciable effect on cell shortening and peak Ca 2ϩ transient at baseline.…”

Section: Transient and Cell Shortening In Normal And Failing Myocytesmentioning

confidence: 99%

Correction of Defective Interdomain Interaction Within Ryanodine Receptor by Antioxidant Is a New Therapeutic Strategy Against Heart Failure

et al. 2005

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Background-Defective interdomain interaction within the ryanodine receptor (RyR2) seems to play a key role in the pathogenesis of heart failure, as shown in recent studies. In the present study we investigated the effect of oxidative stress on the interdomain interaction, its outcome in the cardiac function in heart failure, and the possibility of preventing the problem with antioxidants. Methods and Results-Sarcoplasmic reticulum (SR) vesicles were isolated from dog left ventricular (LV) muscle (normal or rapid ventricular pacing for 4 weeks with or without the antioxidant edaravone). In the edaravone-treated paced dogs (EVϩ), but not in the untreated paced dogs (EVϪ), normal cardiac function was restored almost completely. In the SR vesicles isolated from the EVϪ, oxidative stress of the RyR2 (reduction in the number of free thiols) was severe, but it was negligible in EVϩ. The oxidative stress of the RyR2 destabilized interdomain interactions within the RyR2 (EVϪ), but its effect was reversed in EVϩ. Abnormal Ca 2ϩ leak through the RyR2 was found in EVϪ but not in EVϩ. The amount of the RyR2-bound FKBP12.6 was less in EVϪ than in normal dogs, whereas it was restored almost to a normal amount in EVϩ. The NO donor 3-morpholinosydnonimine (SIN-1) reproduced, in normal SR, several abnormal features seen in failing SR, such as defective interdomain interaction and abnormal Ca 2ϩ leak. Both cell shortening and Ca 2ϩ transients were impaired by SIN-1 in isolated normal myocytes, mimicking the pathophysiological conditions in failing myocytes. Incubation of failing myocytes with edaravone restored the normal properties. Conclusions-During the development of heart failure, edaravone ameliorated the defective interdomain interaction of the RyR2. This prevented Ca 2ϩ leak and LV remodeling, leading to an improvement of cardiac function and an attenuation of LV remodeling.

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Na+–Ca2+ exchanger overexpression predisposes to reactive oxygen species-induced injury

Abstract: ROS-induced hypercontracture is due to Ca(2+) entry via NCX which could be triggered by a concomitant substantial increase in [Na(+)](i). Elevated NCX levels predispose to ROS-induced injury, a mechanism likely contributing to myocyte dysfunction and death in heart failure.

Cited by 46 publications

References 39 publications

Transgenic Mice for Real-Time Visualization of cGMP in Intact Adult Cardiomyocytes

Transgenic Mice for Real-Time Visualization of cGMP in Intact Adult Cardiomyocytes

Ca2+/calmodulin-dependent protein kinase II regulates cardiac Na+ channels

Correction of Defective Interdomain Interaction Within Ryanodine Receptor by Antioxidant Is a New Therapeutic Strategy Against Heart Failure

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