An evaluation of a novel chick cardiomyocyte micromass culture assay with two teratogens/embryotoxins associated with heart defects

This study was aimed at determining whether the chick cardiomyocyte micromass (MM) system could be employed to predict the teratogenicity/embryotoxicity of exogenous chemicals. Two documented teratogens/embryotoxins, sodium valproate (the sodium salt of valproic acid; VPA) and all-trans retinoic acid (tRA), were used in the initial phase of the study. White Leghorn 5-day-old embryo hearts were dissociated to produce a cardiomyocyte suspension in Dulbecco's Modified Eagle's Medium. Cultures were incubated at 37 degrees C in 5% CO(2) in air, and observations were made every 24 hours over 5 days, for the detection of beating. Culture viability was assessed by using the resazurin reduction assay for determining culture activity and the kenacid blue assay for determining cell number. It was found that tRA significantly reduced cell activity and beating, whilst not affecting total cell number. VPA up to 500 microM induced no cytotoxicity in the MM cardiomyocyte cultures, whilst all the VPA concentrations tested reduced beating. The results demonstrate the potential of the chick cardiomyocyte MM culture assay to identify teratogens/embryotoxins that alter functionality, which may result in a teratogenic outcome, whilst not causing cytotoxicity (direct embryotoxicity). This could form part of a screen for developmental toxicity related to cardiac function, whilst limb cultures and brain cultures based on the same system could be relevant to teratogenic effects on those tissues.     

Cardiomyocyte proliferation,a target for cardiac regeneration

Cardiac diseases, characterized by cardiomyocyte loss, lead to dramatic impairment of cardiac function and ultimately to congestive heart failure. Despite significant advances, conventional treatments do not correct the defects in cardiac muscle cell numbers and the prognosis of congestive heart failure remains poor. The existence, in adult mammalian heart, of low but detectable cardiomyocyte proliferative capacities has shifted the target of regenerative therapy toward new therapeutical strategy. Indeed, the stimulation of terminally differentiated cardiomyocyte proliferation represents the main therapeutic approach for heart regeneration. Increasing evidence demonstrating that the loss of mammalian cardiomyocyte renewal potential shortly after birth causes the loss of regenerative capacities, strongly support the hypothesis that a detailed understanding of the molecular mechanisms controlling fetal and postnatal cardiomyocyte proliferation is essential to identify targets for cardiac regeneration. Here, we will review major developmental mechanisms regulating fetal cardiomyocyte proliferation and will describe the impact of the developmental switch, operating at birth and driving postnatal heart maturation, on the regulation of adult cardiomyocyte proliferation, all these mechanisms representing potential targets for cardiac repair and regeneration.     

A cellular test system expressing hERG K+ channels for assaying drug cardiotoxicity: Elaboration and analysis

Many drugs are cardiotoxic because they inhibit hERG K⁺ channels, thus prolonging the repolarization phase of the cardiomyocyte action potential giving rise to cardiac arrhythmias. Early detection of inhibiting effects of candidate drugs on the activity of K⁺ channels in cardiomyocytes is one of the main challenges in preclinical drug screening. The aim of this study was to obtain a cell line expressing recombinant hERG channels at a stable and reproducible level as a prerequisite to its further application as a test system.     

Partial Correction of Abnormal Cardiac Development in Caspase-8-deficient Mice by Cardiomyocyte Expression of p35

Baculovirus p35 protein protects cells from apoptotic cell death by inhibiting caspase activation. We have established transgenic mouse lines specifically expressing p35 in cardiomyocytes, and primary cardiomyocytes isolated from these mice exhibit resistance to staurosporine-induced apoptosis. In a previous study, we observed defects in heart formation associated with abdominal hemorrhage and cardiomyocyte cell death in caspase-8-deficent animals. In order to better understand the etiology of the cardiac defects and embryonic lethality in caspase-8-deficient mice, we crossed these mice with the p35 transgenic animals. Although the newly generated mice still died in utero and exhibited some cardiac defects, cardiomyocyte apoptosis was suppressed and ventricular trabeculation was restored. Thus, cardiomyocyte expression of p35 prevented cell death induced by staurosporine or caspase-8 deficiency. Additionally, our data suggest that caspase-8 plays multiple roles in cardiac development.     

Cardiomyocyte sensor responsive to changes in physical and chemical environments

Conventional cardiac physiology experiments investigate in vitro beat frequency using cells isolated from adult or neonatal rat hearts. In this study, we show that various cantilever shapes and drug treatments alter cardiomyocyte contraction force in vitro. Four types of cantilevers were used to compare the contractile forces: flat, peg patterned, grooved, and peg and grooved. Contraction force was represented as bending deflection of the cantilever end. The deflections of the flat, peg patterned, grooved, and peg and grooved cantilevers were 24.2 nN, 41.6 nN, 121 nN, and 134.2 nN, respectively. We quantified the effect of drug treatments on cardiomyocyte contractile forces on the grooved cantilever using Digoxin, Isoproterenol, and BayK8644, all of which increase contractile force, and Verapamil, which decreases contractile force. The cardiomyocyte contractile force without drugs decreased 8 days after culture initiation. Thus, we applied Digoxin, Isoproterenol, and BayK8644 at day 8, and Verapamil at day 5. Digoxin, Isoproterenol, and BayK8644 increased the cardiomyocyte contractile forces by 19.31%, 9.75%, and 23.81%, respectively. Verapamil decreased the contraction force by 48.06%. In summary, contraction force changes in response to adhesion surface topology and various types of drug treatments. We observed these changes by monitoring cell alignment, adhesion, morphology, and bending displacement with cantilever sensors.     

Subcellular basis of vitamin C protection against doxorubicin-induced changes in rat cardiomyocytes

Understanding the molecular basis of doxorubicin (Dox)-induced cardiomyopathy is crucial to finding cardioprotective strategies. Oxidative stress-mediated pathways are known to contribute to cardiomyocyte apoptosis due to Dox. Improving the antioxidant defenses of cardiomyocytes could be one strategy for cardiac protection. We tested the effects of vitamin C (Vit C), a potent antioxidant, on Dox-induced cardiomyocyte apoptosis. Adult rat cardiomyocytes were incubated for 24 h with Dox (0.01-10 μM), with and without different concentrations of Vit C (5-100 μM). Exposure to Dox (10 μM) resulted in a 98% increase in the production of reactive oxygen species (ROS) and creatine kinase (CK) release, 70% increase in p53 as well as ASK-1 activation, 40% increase in p38 activation, 30% increase in pro-apoptotic Bax over anti-apoptotic Bcl-xl ratio and caspase activation, and about 20% reduction in cell viability. Vit C (25 μM) was able to mitigate Dox-induced changes by decreasing ROS and CK release by 50%, reducing p53 activation by 40%. The increase in ASK-1 and p38 was also significantly mitigated, and apoptosis was reduced while cardiomyocytes viability was improved. This study shows that Dox-induced cardiomyocyte death is mediated by a direct membrane effect as well as intracytoplasmic changes promoting the cardiomyocyte apoptosis. These findings suggest a nutritional approach of using Vit C for preventing Dox-induced cardiotoxicity and better management of cancer patients.     

Expression of alternatively spliced variants of Na–Ca-exchanger-1 in experimental colitis: role in reduced colonic contractility

In an earlier article, we demonstrated that sydnone SYD-1 (3-[4-chloro-3-nitrophenyl]-1,2,3-oxadiazolium-5-olate) inhibits electron transport in the respiratory chain and uncouples oxidative phosphorylation, and postulated that these effects are probably involved in its antitumor activity. We now report the effect of SYD-1 on certain macrophage functions, considering the important role of these cells in inflammatory response and also the relevant anti-inflammatory activity reported for some sydnones. Incubation of macrophages with SYD-1 (5-100 μM) for 48 h did not affect the cell viability up to a concentration of 50 μM. However, at the highest concentration (100 μM), the compound decreased macrophage viability by ~20%. In assays involving 2 h and 24 h of incubation, SYD-1 (5-100 μM) did not affect the cell viability. The incubation of macrophages with the compound for 2 h promoted a dose-dependent reduction of phagocytic activity of up to ~65% (100 μM). SYD-1 (100 μM) was also able to increase the production of superoxide anion (~50%). In the absence of LPS, SYD-1 decreased NO production dose-dependently by up to ~80% (100 μM). When SYD-1 and LPS were incubated concomitantly, the decrease of NO promoted by SYD was the most pronounced, reaching up to ~98% at the same concentration (50 μM). SYD-1 dose-dependently suppressed IL-6 secretion by LPS-stimulated macrophages, reaching up to ~90% of inhibition at the highest concentration (100 μM). These results indicate that SYD-1 promotes effects similar to those described for anti-inflammatory and immunosuppressive drugs, thus motivating further studies to clarify the mechanisms involved in this activity.     

Development of a bioassay from isolated digestive gland cells of the cuttlefish Sepia officinalis L. (Mollusca Cephalopoda): effect of Cu, Zn and Ag on enzyme activities and cell viability

The purpose of this study was to establish a bioassay from isolated digestive gland cells of the cuttlefish Sepia officinalis in order to observe the effect of heavy metals on digestive enzyme activities. Digestive cells were isolated using a pronase enzyme that was removed by several washings of the cell suspension. Cell viability was tested by the MTT assay (3-4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium) and microscopic analysis. The results showed that isolated digestive cells could be maintained 24 h with preservation of whole digestive functionality, measured in terms of MTT test. In fact, the viability was maintained at a high level during 24 h and the intra- and extracellular digestive enzyme activities became stabilised rapidly. Furthermore, suspension cells responded to calcium ionophore and 8-Bromo-cAMP by an unspecific secretion of extracellular digestive enzyme, trypsin, which demonstrated that isolated digestive cells were functional. Using the bioassay, ecotoxicological studies showed that heavy metals could have effects on digestive enzyme activities after 24 h of an incubation time of the metal with the cells. In fact, zinc and silver affected trypsin and/or cathepsins specific activity of the cells. On the contrary, copper had no effect on digestive enzyme activities. Zinc, which is a trace element in all living animals, generated two different responses of cathepsins and cell viability. At a low concentration (0.02 μM), it increased viability and cathepsins specific activity, whereas at a high concentration (0.02 mM), zinc inhibited the cathepsins specific activity with an inhibition of cathepsins. For silver, whatever the tested concentration (0.02 mM or 0.02 μM), it has no impact on digestive gland isolated cell viability. Nevertheless, heavy metal induced high disturbance of enzymatic systems.     

Myostatin Is Upregulated Following Stress in an Erk-Dependent Manner and Negatively Regulates Cardiomyocyte Growth in Culture and in a Mouse Model

Myostatin is well established as a negative regulator of skeletal muscle growth, but its role in the heart is controversial. Our goal in this study was to characterize myostatin regulation following cardiomyocyte stress and to examine the role of myostatin in the regulation of cardiomyocyte size. Neonatal cardiomyocytes were cultured and stressed with phenylephrine. Adenovirus was used to overexpress myostatin or dominant negative myostatin in culture. Adeno-associated virus was used to overexpress myostatin or dominant negative myostatin in mice. Myostatin is upregulated following cardiomyocyte stress in an Erk-dependent manner that is associated with increased nuclear translocation and DNA binding activity of MEF-2. Myostatin overexpression leads to decreased and myostatin inhibition to increased cardiac growth both in vitro and in vivo due to modulation of Akt and NFAT3 pathways. Myostatin is a negative regulator of cardiac growth, and further studies are warranted to investigate the role of myostatin in the healthy and failing heart.     

Cardiomyocyte precursors and telocytes in epicardial stem cell niche: electron microscope images

A highly heterogeneous population of stem and progenitor cells has been described by light immunohistochemistry in the mammalian adult heart, but the ultrastructural identity of cardiac stem cells remains unknown. Using electron microscopy, we demonstrate the presence of cells with stem features in the adult mouse heart. These putative cardiac stem cells are small (6–10 μm), round cells, with an irregular shaped nucleus, large nucleolus, few endoplasmic reticulum cisternae and mitochondria, but numerous ribosomes. Stem cells located in the epicardial stem cell niche undergo mitosis and apoptosis. Cells with intermediate features between stem cells and cardiomyocyte progenitors have also been seen. Moreover, electron microscopy showed that cardiomyocyte progenitors were added to the peripheral working cardiomyocytes. Telocytes make a supportive interstitial network for stem cells and progenitors in the stem cell niche. This study enhances the hypothesis of a unique type of cardiac stem cell and progenitors in different stages of differentiation. In our opinion, stem cells, cardiomyocyte progenitors and telocytes sustain a continuous cardiac renewal process in the adult mammalian heart.     

BMP and Notch Signaling Pathways differentially regulate Cardiomyocyte Proliferation during Ventricle Regeneration

Adult mammalian hearts show limited capacity to proliferate after injury, while zebrafish are capable to completely regenerate injured hearts through the proliferation of spared cardiomyocytes. BMP and Notch signaling pathways have been implicated in cardiomyocyte proliferation during zebrafish heart regeneration. However, the molecular mechanism underneath this process as well as the interaction between these two pathways remains to be further explored. In this study we showed BMP signaling was activated after ventricle ablation and acted epistatic downstream of Notch signaling. Inhibition of both signaling pathways differentially influenced ventricle regeneration and cardiomyocyte proliferation, as revealed by time-lapse analysis using a cardiomyocyte-specific FUCCI (fluorescent ubiquitylation-based cell cycle indicator) system. Further experiments revealed that inhibition of BMP and Notch signaling led to cell-cycle arrest at different phases. Overall, our results shed light on the interaction between BMP and Notch signaling pathways and their functions in cardiomyocyte proliferation during cardiac regeneration.     

Design,Synthesis, and Biological Activity of Guaiazulene Derivatives

Guaiazulene and related derivatives were famous for diverse biological activities. In an effort to discover new highly efficient candidate drugs derived from guaiazulene, four series of guaiazulene derivatives were designed, synthesized, and evaluated for antiproliferation, antiviral, anti-inflammatory and peroxisome proliferators-activated receptor γ (PPARγ) signalling pathway agonist activities. Among them, two guaiazulene condensation derivatives showed selective cytotoxic activities towards K562 cell with IC₅₀ values 5.21 μM and 5.14 μM, respectively, accompanied by slight effects on normal cell viability. For the first time, one guaiazulene derivative from series I exhibited potent antiviral activity towards influenza A virus with IC₅₀ of 17.5 μM. A guaiazulene-based chalcone showed higher anti-inflammatory activity than positive drug indomethacin with an inhibitory rate of 34.29 % in zebrafish model in vivo. One guaiazulene-based flavonoid could strongly agitate PPARγ pathway at 20 μM, indicating the potential of guaiazulene derivatives to reduce obesity development and ameliorate hepatic steatosis. Preliminary in silico ADME studies predicted the excellent drug-likeness properties of bioactive guaiazulene derivatives.     

Newborn Hypoxia/Anoxia Inhibits Cardiomyocyte Proliferation and Decreases Cardiomyocyte Endowment in the Developing Heart: Role of Endothelin-1

In the developing heart, cardiomyocytes undergo terminal differentiation during a critical window around birth. Hypoxia is a major stress to preterm infants, yet its effect on the development and maturation of the heart remains unknown. We tested the hypothesis in a rat model that newborn anoxia accelerates cardiomyocyte terminal differentiation and results in reduced cardiomyocyte endowment in the developing heart via an endothelin-1-dependent mechanism. Newborn rats were exposed to anoxia twice daily from postnatal day 1 to 3, and hearts were isolated and studied at postnatal day 4 (P4), 7 (P7), and 14 (P14). Anoxia significantly increased HIF-1α protein expression and pre-proET-1 mRNA abundance in P4 neonatal hearts. Cardiomyocyte proliferation was significantly decreased by anoxia in P4 and P7, resulting in a significant reduction of cardiomyocyte number per heart weight in the P14 neonates. Furthermore, the expression of cyclin D2 was significantly decreased due to anoxia, while p27 expression was increased. Anoxia has no significant effect on cardiomyocyte binucleation or myocyte size. Consistently, prenatal hypoxia significantly decreased cardiomyocyte proliferation but had no effect on binucleation in the fetal heart. Newborn administration of PD156707, an ET_A-receptor antagonist, significantly increased cardiomyocyte proliferation at P4 and cell size at P7, resulting in an increase in the heart to body weight ratio in P7 neonates. In addition, PD156707 abrogated the anoxia-mediated effects. The results suggest that hypoxia and anoxia via activation of endothelin-1 at the critical window of heart development inhibits cardiomyocyte proliferation and decreases myocyte endowment in the developing heart, which may negatively impact cardiac function later in life.     

Acrolein,an Environmental Toxin,Induces Cardiomyocyte Apoptosis via Elevated Intracellular Calcium and Free Radicals

Acrolein, an unsaturated aldehyde, is an environmental toxin known to inhibit mitochondrial electron transport chain in brain and induce lipid peroxidation and apoptosis. However, the nature of the effects of acrolein on cardiac function and myocardium is not known. The objective of this study is to examine whether acrolein induces apoptosis in cardiomyocytes and alters cytosolic calcium concentration and the intracellular oxygen free-radical levels. Adult mouse cardiomyocytes exposed to 1 μmol/l of acrolein showed a marked increase in the intracellular oxygen free-radicals and calcium concentration, by 12- and 2-fold, respectively, compared to the resting value. Moreover, the cardiomyocyte viability decreased significantly in a dose-dependent manner by treatment with 25, 50, and 100 μmol/l of acrolein compared to controls. Morphological changes and DNA laddering typical of apoptosis were found in acrolein-exposed cardiomyocytes. Our finding suggested that acrolein caused apoptotic death of adult mice cardiomyocytes by increasing intracellular oxygen free-radicals and calcium concentration.     

线粒体乙醛脱氢酶2(ALDH2)通过AMPK/FOXO3a通路改善高糖导致的心肌细胞凋亡

目的:观察乙醛脱氢酶2(ALDH2)对高糖诱导的H9C2心肌细胞存活及凋亡的影响,并探讨腺苷酸活化蛋白激酶(AMPK)/FOXO3a信号通路在高糖导致的心肌细胞凋亡中的调控作用。方法:以30 mmol/L葡萄糖诱导培养H9C2心肌细胞48 h,经ALDH2激动剂Alda-1及AMPK抑制剂Compound C干预后,用MTT法检测细胞的存活情况,TUNEL试剂盒检测细胞凋亡情况,Western blot检测ALDH2、磷酸化AMPK和FOXO3a蛋白的表达水平。结果:与对照组相比,高浓度葡萄糖培养H9C2心肌细胞后,细胞的存活率显著降低、凋亡指数明显升高,磷酸化AMPK的表达水平明显上调,ALDH2和磷酸化FOXO3a的蛋白表达显著降低(P0.05)。ALDH2的激动剂Alda-1处理可显著提高高糖诱导的H9C2心肌细胞的存活率、降低其凋亡率,减少磷酸化AMPK的蛋白表达,增加ALDH2的表达和FOXO3a蛋白的磷酸化;而进一步采用AMPK的抑制剂Compound C处理,可显著抑制Alda-1对高糖诱导的H9C2心肌细胞的这些影响。结论:ALDH2的激动剂Alda-1对高糖诱导的心肌细胞凋亡具有保护作用,可能与其激活AMPK,进而抑制心肌细胞FOXO3a的活性有关。     

Adiponectin mediates cardioprotection in oxidative stress-induced cardiac myocyte remodeling

Reactive oxygen species (ROS) induce matrix metalloproteinase (MMP) activity that mediates hypertrophy and cardiac remodeling. Adiponectin (APN), an adipokine, modulates cardiac hypertrophy, but it is unknown if APN inhibits ROS-induced cardiomyocyte remodeling. We tested the hypothesis that APN ameliorates ROS-induced cardiomyocyte remodeling and investigated the mechanisms involved. Cultured adult rat ventricular myocytes (ARVM) were pretreated with recombinant APN (30 μg/ml, 18 h) followed by exposure to physiologic concentrations of H(2)O(2) (1-200 μM). ARVM hypertrophy was measured by [(3)H]leucine incorporation and atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) gene expression by RT-PCR. MMP activity was assessed by in-gel zymography. ROS was induced with angiotensin (ANG)-II (3.2 mg·kg(-1)·day(-1) for 14 days) in wild-type (WT) and APN-deficient (APN-KO) mice. Myocardial MMPs, tissue inhibitors of MMPs (TIMPs), p-AMPK, and p-ERK protein expression were determined. APN significantly decreased H(2)O(2)-induced cardiomyocyte hypertrophy by decreasing total protein, protein synthesis, ANF, and BNP expression. H(2)O(2)-induced MMP-9 and MMP-2 activities were also significantly diminished by APN. APN significantly increased p-AMPK in both nonstimulated and H(2)O(2)-treated ARVM. H(2)O(2)-induced p-ERK activity and NF-κB activity were both abrogated by APN pretreatment. ANG II significantly decreased myocardial p-AMPK and increased p-ERK expression in vivo in APN-KO vs. WT mice. ANG II infusion enhanced cardiac fibrosis and MMP-2-to-TIMP-2 and MMP-9-to-TIMP-1 ratios in APN-KO vs. WT mice. Thus APN inhibits ROS-induced cardiomyocyte remodeling by activating AMPK and inhibiting ERK signaling and NF-κB activity. Its effects on ROS and ultimately on MMP expression define the protective role of APN against ROS-induced cardiac remodeling.     

Daunomycin disrupts nuclear assembly and the coordinate initiation of DNA replication in Xenopus egg extracts

We have used Xenopus egg extracts to investigate the effects of the antitumor drug daunomycin on DNA replication in vitro. Xenopus sperm nuclei replicated nearly synchronously in our egg extracts, thereby allowing us to determine the effects of the drug on both replication initiation and elongation. Titration experiments demonstrated that daunomycin effectively inhibited replication in the extract, with 50% inhibition at a total drug concentration of 2.7 μM. However, a high concentration of daunomycin 150 μM) also inhibited nuclear envelope assembly, a prerequisite for the initiation of replication in this system. Therefore, to bypass the effects of daunomycin on nuclear envelope assembly, sperm nuclei were preassembled in extract prior to drug addition. Initiation of replication in preassembled nuclei was also inhibited by daunomycin, with 50% inhibition at a drug concentration of 3.6 μM. At low drug concentrations, where replication did occur, the synchrony of initiations within individual nuclei was lost. This drug-induced disruption of initiation events may provide important clues regarding the mechanism(s) by which these events are coordinated in eukaryotic cells. Daunomycin also inhibited replication elongation in preassembled, preinitiated nuclei. However, the concentration of drug required for 50% inhibition of elongation was nearly fourfold higher than that required for inhibition of initiation. Taken together, these data demonstrate that Xenopus egg extract can be used to investigate the effects of DNA-binding antitumor drugs on a number of interrelated cellular processes, many of which are less tractable in whole cell systems. J. Cell. Biochem. 64:476–491. © 1997 Wiley-Liss, Inc.     

The Soluble Guanylyl Cyclase Activator Bay 58-2667 Selectively Limits Cardiomyocyte Hypertrophy

Background

Although evidence now suggests cGMP is a negative regulator of cardiac hypertrophy, the direct consequences of the soluble guanylyl cyclase (sGC) activator BAY 58-2667 on cardiac remodeling, independent of changes in hemodynamic load, has not been investigated. In the present study, we tested the hypothesis that the NO^•-independent sGC activator BAY 58-2667 inhibits cardiomyocyte hypertrophy in vitro. Concomitant impact of BAY 58-2667 on cardiac fibroblast proliferation, and insights into potential mechanisms of action, were also sought. Results were compared to the sGC stimulator BAY 41-2272.

Methods

Neonatal rat cardiomyocytes were incubated with endothelin-1 (ET₁, 60nmol/L) in the presence and absence of BAY 41-2272 and BAY 58-2667 (0.01–0.3 µmol/L). Hypertrophic responses and its triggers, as well as cGMP signaling, were determined. The impact of both sGC ligands on basal and stimulated cardiac fibroblast proliferation in vitro was also determined.

Results

We now demonstrate that BAY 58-2667 (0.01–0.3 µmol/L) elicited concentration-dependent antihypertrophic actions, inhibiting ET₁-mediated increases in cardiomyocyte 2D area and de novo protein synthesis, as well as suppressing ET₁-induced cardiomyocyte superoxide generation. This was accompanied by potent increases in cardiomyocyte cGMP accumulation and activity of its downstream signal, vasodilator-stimulated phosphoprotein (VASP), without elevating cardiomyocyte cAMP. In contrast, submicromolar concentrations of BAY 58-2667 had no effect on basal or stimulated cardiac fibroblast proliferation. Indeed, only at concentrations ≥10 µmol/L was inhibition of cardiac fibrosis seen in vitro. The effects of BAY 58-2667 in both cell types were mimicked by BAY 41-2272.

Conclusions

Our results demonstrate that BAY 58-2667 elicits protective, cardiomyocyte-selective effects in vitro. These actions are associated with sGC activation and are evident in the absence of confounding hemodynamic factors, at low (submicromolar) concentrations. Thus this distinctive sGC ligand may potentially represent an alternative therapeutic approach for limiting myocardial hypertrophy.