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Circulation. 1999;100:305-311

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(Circulation. 1999;100:305-311.)
© 1999 American Heart Association, Inc.


Basic Science Reports

{alpha}- and ß-Adrenergic Pathways Differentially Regulate Cell Type–Specific Apoptosis in Rat Cardiac Myocytes

Eri Iwai-Kanai, MD; Koji Hasegawa, MD, PhD; Makoto Araki, MD; Tsuyoshi Kakita, MD; Tatsuya Morimoto, MD; Shigetake Sasayama, MD, PhD

From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.

Correspondence to Koji Hasegawa, MD, PhD, Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, 54 Kawara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan. E-mail koj{at}kuhp.kyoto-u.ac.jp


*    Abstract
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Background—The apoptosis of cardiac myocytes may play a role in the development of heart failure. Norepinephrine is one of the factors activated in heart failure and can induce myocardial cell apoptosis in culture. However, it is unknown if {alpha}- and ß-adrenergic pathways coordinately or differentially regulate apoptosis and if this apoptotic pathway uses common or cell type–specific apoptotic signals.

Methods and Results—We stimulated cultured neonatal rat cardiac myocytes with an {alpha}1-adrenergic agonist (PE, phenylephrine), a ß-adrenergic agonist (isoproterenol [Iso]) or a membrane-permeable cAMP analogue (8-Br-cAMP) in serum-free conditions for 48 hours. Iso and 8-Br-cAMP markedly increased the number of TUNEL-positive cells (%TUNEL-positive nuclei >40%) compared with saline stimulation (<10%). DNA fragmentation was also confirmed by ladder formation in agarose gels. Apoptotic myocytes were characterized by cell shrinkage and nuclear condensation, consistent with morphological features of apoptosis. The Iso-induced apoptosis was almost completely inhibited by the protein kinase A–specific inhibitor KT5720. In contrast, PE inhibited 8-Br-cAMP–induced myocardial cell apoptosis. The apoptosis-inhibitory effect by PE was negated by the {alpha}1-adrenergic receptor antagonist prazosin and the MEK-1–specific inhibitor PD098059. Interestingly, although 8-Br-cAMP markedly induced apoptosis in cardiac myocytes, it completely blocked serum depletion–induced apoptosis in PC12 cells, a rat pheochromocytoma cell line.

Conclusions—These findings indicate that {alpha}- and ß-adrenergic pathways differentially regulate myocardial cell apoptosis. The results also suggest that a cAMP– protein kinase A pathway is necessary and sufficient for ß-adrenergic agonist–induced apoptosis and that this apoptotic pathway is not functional in other cell types, for example, PC12 cells.


Key Words: apoptosis • myocytes • heart failure


*    Introduction
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Apoptosis, or programmed cell death, is a central feature of normal tissue development in the fetus and of cell replacement in certain adult tissues (eg, thymus).1 2 3 4 5 In contrast to the classic swelling and membrane rupture associated with necrosis, apoptotic cells shrink and maintain their membrane integrity. The hallmarks of apoptosis include cell shrinkage, membrane blebbing, chromatin condensation, and DNA fragmentation. Apoptotic cells are phagocytosed by neighboring cells, effectively removing unwanted cells without an inflammatory response. Apoptosis is most often associated with cells that are progressing through the cell cycle. Although adult cardiac myocytes are terminally differentiated and have lost their ability to divide, accumulating evidence suggests that these cells can undergo apoptosis in vivo in various animal models of heart failure including models of rapid ventricular pacing6 7 and pressure overload caused by aortic constriction8 and aged spontaneously hypertensive rats.9 Since the functional aspects of the failing myocardium are impaired in proportion to the reduction in the myocyte fractional area, the apoptosis of myocytes may play a significant role in the deterioration of cardiac function. As such, the identification of the signaling pathways that mediate cardiac myocyte cell death and survival is critical to the ultimate elucidation of the molecular basis of cardiac muscle failure.

Despite an increasing body of evidence concerning myocardial cell apoptosis in vivo, little is known regarding the relevant physiological stimuli. The control of programmed cell death is dependent on a balance between inhibitors and inducers of apoptosis. Since a number of neurohormonal factors are activated in congestive heart failure,10 11 they may play positive and negative roles in regulating myocardial cell apoptosis. Norepinephrine is one such factor, the elevation of which in plasma closely correlates with the severity and poor prognosis of heart failure.11 It was recently shown that norepinephrine can induce apoptosis in cardiac myocytes in vitro.12 Norepinephrine exerts its effect on cardiac myocytes through both {alpha}- and ß-adrenergic receptor pathways. However, it is not known whether {alpha}- and ß-adrenergic pathways regulate apoptosis in a coordinated or differential manner.

Apoptosis in other cell types has been extensively studied. Several reports suggest that a subset of apoptosis inducers is common in cardiac myocytes. For example, reactive oxygen species and tumor necrosis factor-{alpha}, both of which are potent apoptosis inducers in most cell types,12 13 14 15 16 17 have also been implicated in myocardial cell apoptosis.18 19 It was recently reported that p53, a well-known trigger of apoptosis in a variety of cell types, is sufficient to trigger apoptosis by itself in cardiac myocytes.20 21 However, cardiac muscle cells are distinct from other cell types in many biological aspects. Because the signaling pathways leading to apoptosis differ among cell types, it is likely that in addition to the conserved pathways, cardiac myocytes possess their own apoptotic pathways. It is unknown, however, whether norepinephrine-induced apoptosis occurs in a cell type–specific manner or uses common apoptotic signals.

The present study investigated the effects of {alpha}- and ß-adrenergic stimulation on myocardial cell apoptosis. In this study, we show that a cAMP– protein kinase A (PKA) pathway is necessary and sufficient for ß-adrenergic stimulation–induced apoptosis, whereas MEK-1 appears to be involved in an inhibitory effect by {alpha}1-adrenergic stimulation. Interestingly, in contrast to cardiac myocytes, cAMP almost completely inhibited apoptosis in PC12 cells, a pheochromocytoma cell line, suggesting that this cAMP-PKA apoptotic pathway might use some cardiac-specific machinery.


*    Methods
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Cell Culture
Primary ventricular cardiac myocytes were prepared as previously described.22 Briefly, hearts from 1- to 2-day-old Sprague-Dawley rats were removed, the ventricles were pooled, and the ventricular cells were dispersed by digestion with pancreatin (Life Technologies). The cells were preplated for 1 hour to enrich the culture with myocytes (90% to 95% of cells after this step). Cells were plated at a high density (1000 cells/mm2) onto 60-mm tissue culture dishes (Primaria, Falcon; Becton Dickinson & Co) and cultured in media consisting of Hanks' salts plus minimal essential medium (MEM) vitamin stock, MEM amino acids, MEM nonessential amino acids, 2 mmol/L L-glutamine, 0.67 mmol/L glycine, 0.92 mmol/L hypoxanthine, 19.6 mmol/L NaHCO3 (pH 7.1 to 7.2), penicillin, streptomycin, and 10% (vol/vol) fetal bovine serum (all from GIBCO BRL) at 37°C, 5% CO2.

PC12 cells, a rat pheochromocytoma cell line, were obtained from a health science research resources bank (JCRB No. 0733) and kept in the RPMI 1640 medium with 10% horse serum and 5% fetal bovine serum.

Nucleosomal Ladder Assay
Forty-eight hours after plating, the neonatal rat cardiac myocytes were washed twice with serum-free media and cultured in serum-free medium in the presence or absence of phenylephrine (PE), isoproterenol (Iso) or 8-B-cAMP for 48 hours. These agents were obtained from Sigma and were of the highest purity available. The cells were then harvested by scraping into the media. After centrifugation at 500g for 5 minutes at 4°C, the cells were lysed in lysis buffer and subjected to a nucleosomal ladder assay with the use of a commercial kit (Takara Biomedicals) according to the manufacturer's recommendations. The presence of characteristic 180- to 200-bp multiple oligonucleosomal fragmentation was examined on 1.5% agarose gels stained with SYBR Green I (Takara Biomedicals).

In Situ Labeling of Apoptotic Cells and Quantitative Analysis
Terminal deoxynucleotidyl transfer–mediated end-labeling of fragmented nuclei (TUNEL assay) was performed on cardiomyocytes that had been plated on flask-style glass slides (Nalgen Nunc). The in situ TUNEL assay was then performed in accordance with the manufacturer's protocol for cultured cells (Takara Biomedicals) after fixing the cells in 10% neutral buffered formalin for 10 minutes at room temperature. Individual nuclei were visualized at a magnification of x400 for quantitative analysis. An average of 400 to 500 nuclei from random fields were analyzed in each slide. The apoptotic index (percentage of apoptotic nuclei) was calculated as (apoptotic nuclei/total nuclei)x100%. Sample indicates were concealed during scoring, and samples from at least 3 independent experiments were scored per group.

Immunocytochemistry
To identify cardiac myocytes, immunocytochemical staining was performed as described23 24 with the use of a monoclonal antibody against muscle-specific {alpha}-actin (HHF35) at a dilution of 1:100. Signals were detected with the use of an alkaline phosphatase–conjugated Fab fragment of the secondary antibody (a dilution of 1:600, Jackson Immunoresearch Laboratories) and nitroblue tetrazolium dye as the substrate.

Statistical Analysis
Data are presented as mean±SE. Statistical comparisons were performed with the use of unpaired 2-tailed Student's t tests or ANOVA with Scheffé's test when appropriate, with a probability value of <0.05 taken to indicate significance.


*    Results
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ß-Adrenergic Stimulation Activates an Apoptotic Program in Cardiac Myocytes
For the investigation of the possible contribution of a ß-adrenergic pathway to the development of myocardial cell apoptosis, neonatal rat cardiac myocytes were treated with a ß-adrenergic agonist (Iso) or saline as a control in the serum-free condition. In our experimental conditions in which cells were plated at a high density, serum deprivation alone did not increase the number of TUNEL-positive nuclei (<10%) (Figure 1ADown). As shown in Figure 1BDown, however, the stimulation with Iso markedly increased the number of TUNEL-positive cells (>40%). These positive cells may specifically indicate the presence of internucleosomal DNA fragmentation, since no positive cells were found when we omitted the terminal deoxytransferase treatment (Figure 1CDown). The cells stimulated with Iso displayed small condensed nuclei, cell shrinkage, and nuclear fragmentation, consistent with the morphological features of apoptosis (Figures 1CDown and 1DDown). These cells were derived from cardiac myocytes, as evidenced by the positive immunostaining for HHF35, which reacts with the {alpha}-actin of cardiac myocytes but not that of fibroblasts (Figure 1DDown). Figure 2Down and Figure 4Down show the Iso-induced typical ladder formation of fragmented internucleosomal DNA in agarose gels, a hallmark of apoptosis. The Iso-induced apoptosis occurred in a dose-dependent manner, as shown in Figure 3Down. Apoptosis was evident later than 36 hours but not at 24 hours after Iso stimulation (data not shown). The Iso-induced apoptosis was almost completely blocked by a ß-adrenergic receptor antagonist, propranolol (10-4 mol/L) (Figure 2Down, lane 3 and Figure 5Down, lane 5), whereas this concentration of propranolol alone did not increase the number of TUNEL-positive cells (Figure 5Down, lane 2). To further test the specificity of propranolol, we examined the effect of this agent on 8-Br-cAMP–induced apoptosis. We found that 10-4 mol/L propranolol did not affect the 8-Br-cAMP–stimulated increase of TUNEL-positive cells (compare Figure 5Down, lanes 7 and 8). These findings provide evidence that a ß-adrenergic receptor–dependent pathway activates an apoptotic program in cardiac myocytes.



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Figure 1. Induction of apoptosis in cultured neonatal rat cardiac myocytes by Iso stimulation. A, In the absence of Iso; B through E, in the presence of Iso. A through C, TUNEL-stained myocytes. Terminal deoxytransferase was omitted in C. D and E, Stained with HHF35 and secondary antibody conjugated with alkaline-phosphatase. Primary antibody was substituted with PBS in E. Arrowheads show cells with evidence of apoptosis, including chromatin condensation.



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Figure 2. Fragmentation of genomic DNA from Iso-stimulated cardiac myocytes. Genomic DNA was isolated from myocytes maintained for 48 hours in serum-free media in the presence or absence of Iso (10-4 mol/L) and propranolol (10-4 mol/L) as indicated and loaded on a 1.5% agarose gel. Ladder assays were performed in 3 independent experiments; data presented are representative. M indicates molecular marker.



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Figure 4. PKA is required for Iso-induced apoptosis. Genomic DNA was isolated from myocytes maintained for 48 hours in serum-free media in presence or absence of Iso (10-4 mol/L) and KT5720 (10-6 mol/L) as indicated. Ladder assays were performed in 3 independent experiments; data presented are representative. M indicates molecular marker.



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Figure 3. Dose-dependence of Iso-induced apoptosis. Cultured cardiac myocytes were treated for 48 hours with indicated concentrations of Iso or PE. TUNEL-positive nuclei were counted and expressed as percentage of total nuclei. An average of 400 to 500 nuclei were counted from random fields in each slide. Results are mean±SE of 3 independent experiments. *P<0.001 vs saline and Iso 10-8 mol/L; P<0.05 vs Iso 10-6 mol/L. **P<0.05 vs saline.



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Figure 5. Specificity of propranolol and KT5720 on inhibition of Iso-induced apoptosis. Cultured cardiac myocytes were treated for 48 hours in presence or absence of Iso (10-4 mol/L), Br-cAMP (30 mmol/L), propranolol (10-4 mol/L), and KT5720 (10-6 mol/L) as indicated. %TUNEL-positive nuclei was calculated by counting an average of 400 to 500 nuclei in each slide. Results are mean±SE of 3 independent experiments.

cAMP/PKA Pathway Mediates Iso-Induced Apoptosis
Stimulation of the ß-adrenergic receptor activates adenylate cyclase, which increases intracellular cAMP and activates cAMP-dependent PKA. To determine whether the activation of PKA is required for Iso-induced apoptosis, we examined the effect of KT5720, a highly selective inhibitor of PKA.25 As shown in Figure 4Up, 10-6 mol/L of KT5720 was able to completely inhibit the Iso-induced internucleosomal cleavage of genomic DNA. The quantitative analysis by TUNEL staining also revealed that KT5720 (10-6 mol/L) almost completely inhibited the Iso-stimulated increase of TUNEL-positive cells (Figure 5Up, lane 6), whereas the same concentration of this agent alone did not induce apoptosis (Figure 5Up, lane 3). In accord with these results, the administration of a cell-permeable cAMP analogue, 8-Br-cAMP (30 mmol/L), also induced apoptosis in cardiac myocytes to an extent similar to that shown by Iso (Figure 5Up, lane 7 and Figure 6ADown, lane 2). Taken together, these results demonstrate that cAMP-PKA is necessary and sufficient for Iso-induced apoptosis.



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Figure 6. Effects of PD098059 on PE-mediated inhibition of apoptosis. Cardiac myocytes were cultured in serum-free media in presence or absence of 8-Br-cAMP (30 mmol/L), PE (10-4 mol/L), prazosin (10-6 mol/L), and PD098059 (10-5 mol/L) as indicated for 48 hours. A, Genomic DNA isolated from these myocytes was loaded on a 1.5% agarose gel. Ladder assays were performed in 3 independent experiments; data presented are representative. M indicates molecular marker. B, %TUNEL-positive nuclei was calculated by counting an average of 400 to 500 nuclei in each slide. Values are mean±SE of 3 independent experiments.

{alpha}1-Adrenergic Pathway Inhibits cAMP-Induced Cardiac Apoptosis
To determine the effects of {alpha}1-adrenergic stimulation on myocardial cell apoptosis, neonatal rat cardiac myocytes were treated with an {alpha}1-adrenergic agonist (PE). In contrast to Iso, stimulation with PE did not increase the number of TUNEL-positive cells, even at a high concentration (10-4 mol/L) (Figure 3Up). As shown in Figure 6AUp, lane 3, PE inhibited the internucleosomal cleavage of genomic DNA in 8-Br-cAMP–stimulated cardiac myocytes. The antiapoptotic effect of PE was further revealed by TUNEL staining (Figure 6BUp). Fewer myocardial cells treated with PE in addition to 8-Br-cAMP were positive for internucleosomal cleavage by TUNEL staining (Figure 6BUp, lane 5) compared with the cells treated with 8-Br cAMP alone (Figure 6BUp, lane 4). These results provide evidence that PE has an antiapoptotic effect in cultured cardiac myocytes. To evaluate whether the inhibition of myocardial apoptosis by PE is mediated through an {alpha}1-adrenergic receptor pathway, we used prazosin, an {alpha}1-adrenergic receptor antagonist. Prazosin negated the PE-mediated inhibition of apoptosis (Figure 6BUp, lane 6), whereas the same concentration of this agent did not increase the number of TUNEL-positive cells (Figure 6BUp, lane 2) compared with saline stimulation (Figure 6BUp, lane 1).

{alpha}1-Adrenergic stimulation has been shown to activate a MAP kinase cascade in cardiac myocytes. To determine whether the activation of MAP kinase is required for the PE inhibition of apoptosis in cardiac myocytes, we used PD098059, a specific MEK inhibitor that selectively inhibits MEK-1 activity.26 27 A previous study confirmed that 10 µM of PD098059 completely inhibits the PE-stimulated activation of ERK1 and ERK2 in cardiac myocytes.28 As shown in Figure 6AUp, lane 4, and Figure 6BUp, lane 7, 10 µM of PD098059 negated the inhibitory effects of PE on myocardial cell apoptosis. To exclude the possibility of a nonspecific cytotoxic effect of PD098059, we tested whether it was capable of inducing cell death in the serum-free condition. We found that 10 µM or 50 µM of PD098059 alone did not induce apoptosis (Figure 6BUp, lane 3) compared with saline stimulation (Figure 6BUp, lane 1). This result suggested that PD098059 might block the downstream signaling pathway by which PE prevents apoptosis. Taken together, these results provide evidence that PE has an antiapoptotic effect in cultured cardiac myocytes and that a MAP kinase pathway appears to be involved in this process.

cAMP-Mediated Apoptotic Pathway Is Not Functional in PC12 Cells
In cardiac myocytes, as shown in Figure 7ADown, serum deprivation alone barely induced internucleosomal cleavage of genomic DNA compared with the condition of 10% fetal bovine serum. Cell-permeable 8-Br-cAMP induced marked apoptosis in the serum-free condition (Figure 7ADown, lane 3). To determine whether cAMP-induced apoptosis is a conserved phenomenon among different cell types or a phenomenon unique to cardiac myocytes, we examined the effect of 8-Br-cAMP on apoptosis in different cell lines. For this purpose, we used PC12 cells, rat pheochromocytoma cells that are dependent on the presence of growth factors such as nerve growth factor and insulin growth factor-1 in the medium and die by apoptosis after serum deprivation.29 30 In these cells, 12 hours after serum deprivation, marked internucleosomal cleavage of genomic DNA was observed. Notably, as shown in Figure 7BDown, the administration of 30 mmol/L of 8-Br-cAMP completely inhibited the serum deprivation–induced apoptosis in PC12 cells. Antiapoptotic effects of 8-Br-cAMP were also observed in other mitotic cell lines such as mouse fibroblast cells (NIH3T3 cells) (data not shown). These findings indicate that a cAMP pathway is involved in promoting cell survival in these cell lines. Thus 8-Br-cAMP displayed opposite effects on apoptosis in cardiac myocytes and PC12 cells.



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Figure 7. Effects of 8-Br-cAMP on apoptosis in cardiac myocytes and PC12 cells. Cardiac myocytes or PC12 cells were cultured in serum-free or serum-containing condition with or without Br-cAMP (30 mmol/L) as indicated. Genomic DNA was isolated from these cells and loaded on a 1.5% agarose gel. Ladder assays were performed in 3 independent experiments; data presented are representative. M indicates molecular marker.


*    Discussion
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up arrowAbstract
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up arrowMethods
up arrowResults
*Discussion
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Adult cardiac muscle cells are terminally differentiated and have lost their proliferative capacity. As a result, the maintenance of cardiac muscle cell survival is critical for the maintenance of normal cardiac function. The present study demonstrated that a ß-adrenergic agonist induced apoptosis in cardiac myocytes and that this apoptosis was mediated through a cAMP-PKA pathway. In contrast, an {alpha}1-adrenergic agonist antagonized cAMP-induced apoptosis. Interestingly, cAMP had opposite effects on apoptosis in cardiac myocytes and PC12 cells, suggesting that cAMP involves cardiac-specific signal transduction mechanisms.

Accumulating evidence suggests that myocyte apoptosis occurs in failing hearts,6 7 8 9 suggesting that apoptosis contributes to progressive myocardial dysfunction. Nevertheless, little is known about the stimuli that initiate the program of apoptosis or the molecular and cellular events that mediate the ensuing cell death. A number of neurohormonal and autocrine substances, including A-type and B-type natriuretic peptides, endothelin-1, and norepinephrine, are present at high levels in patients with heart failure.10 11 The elevated plasma levels of norepinephrine, an activator of both {alpha}- and ß-adrenergic pathways, is closely associated with the severity and poor prognosis of heart failure.10 11 With the use of 3 independent criteria, that is, TUNEL staining, DNA ladder formation, and nuclear condensation, the present study has documented that ß-adrenergic stimulation can induce apoptosis in cultured neonatal rat cardiac myocytes. In addition, a highly selective inhibitor of PKA, KT5720, completely blocked ß-adrenergic–induced cardiac apoptosis, suggesting a PKA-dependent effect. Consistent with these results, the membrane-permeable cAMP analogue (8-Br-cAMP) also induced apoptosis in these cells. These findings demonstrate that a cAMP-PKA pathway mediates ß-adrenergic–induced apoptosis. Although small numbers of fibroblasts are present in every culture of neonatal myocytes, the apoptosis that resulted from either ß-adrenergic agonist or 8-Br-cAMP was confined to myocytes, as shown by muscle-specific immunostaining with HHF35. Cardiac specificity was also confirmed by the findings that the cellular composition of these cultures was >90% myocytes and that these stimuli did not induce apoptosis in other cell lines such as NIH3T3 or PC12 cells.

We used cultured neonatal cardiac myocytes, which retain some ability to undergo DNA synthesis.31 32 It should be further investigated whether ß-adrenergic stimulation can induce apoptosis in terminal differentiated adult cardiac myocytes in vivo. However, the results of our study are compatible with 2 recent reports: (1) norepinephrine can induce apoptosis in adult cardiac myocytes in culture through a ß-adrenergic pathway12 ; and (2) the overexpression of Gs{alpha} results in the accelerated apoptosis of adult cardiac myocytes in transgenic mice.33 Thus the induction of cardiomyocyte apoptosis through ß-adrenergic receptor–dependent signaling pathways is not confined to in vitro assays in neonatal cells but may also occur in adult cardiac myocytes in vivo.

The present study also demonstrated that {alpha}1-adrenergic stimulation inhibited cAMP-induced apoptosis. {alpha}1-Adrenergic stimulation triggers downstream signaling pathways through Gq{alpha} and subsequently activates protein kinase C. It is also becoming clear that an {alpha}1-adrenergic pathway cross-talks with Ras and MAP kinase cascades. The present treatment of cultured neonatal cardiac myocytes with 10 mmol/L of a MEK-specific inhibitor, PD098059, which has been shown to completely inhibit the PE-stimulated activation of ERK1 and ERK2 at this concentration,28 negated the apoptosis-inhibitory effect of {alpha}1-adrenergic agonist. These findings demonstrate that MAP kinase–dependent pathways are required for the inhibition of cardiac myocyte apoptosis. Our data do not rule out a possible role of MAP kinase–independent pathways in the apoptosis inhibition. However, the nearly complete blockade of the {alpha}1-adrenergic–mediated inhibition of apoptosis by PD098059 suggests the essential role for this pathway in the cell survival function. MAP kinase pathways have been found to be necessary for the effects of nerve growth factor and insulin growth factor-1 on the promotion of the survival of neuronal cell types (PC12), whereas the inhibition of MAP kinase has been shown to be critical for the induction of apoptosis in these cells.29 30 These studies provide further evidence that MAP kinase–dependent pathways play a particularly important role in promoting the survival of terminally differentiated cell types as well.

Another interesting feature of our results is the opposing effects of cAMP on apoptosis in 2 different cell types. In contrast to the data in primary cardiac myocytes in culture, the administration of 8-Br-cAMP completely inhibited serum deprivation–induced apoptosis in PC12 pheochromocytoma cells. Thus cAMP-mediated apoptosis in cardiac myocytes might involve some cell type–specific signal transduction mechanisms. At present, the precise molecular effectors and targets of cAMP-induced cardiac apoptosis are unclear. Regarding apoptosis in terminally differentiated cells, one of the candidate molecules is the adenovirus E1A-associated cellular protein p300, which appears to play a role in myocardial cell survival.32 33 p300 is a homologue of CBP, a protein that is associated with and coactivates the transcription factor CREB, mediating the induction of cAMP-responsive promoters.34 35 The possible involvement of the p300/CBP family in cAMP-mediated apoptosis in cardiac myocytes requires further investigation.

Several lines of evidence suggest that the activation of the sympathetic nervous system exerts a direct deleterious effect on the heart that is independent of the hemodynamic actions of these endogenous mechanisms. Therapeutic interventions by ß-adrenergic receptor blockers favorably alter the natural history of heart failure, and such benefits cannot be explained by the effect of these agents on cardiac contractility and ejection fraction. The present study demonstrated that a ß-adrenergic pathway but not the {alpha}1-adrenergic pathway induced cell type–specific apoptosis in cardiac myocytes. These findings might indicate a mechanism of the beneficial effects of ß-adrenergic receptor blockers in patients with heart failure. It would be of particular interest to test whether ß-adrenergic receptor blockers can inhibit myocyte apoptosis in experimental animal models of heart failure. In addition, the elucidation of precise signaling pathways leading to myocardial cell apoptosis may contribute to novel strategies for heart failure therapy in humans.


*    Acknowledgments
 
This work was supported in part by grants (to Dr Hasegawa) from the Japanese Heart Foundation, the Japan Cardiovascular Research Foundation, Yamanouchi Foundation for Research on Metabolic Disorders, Uehara Memorial Foundation, The Tokyo Biochemical Research Foundation, and the Ministry of Education, Science, and Culture of Japan.

Received November 18, 1998; revision received March 4, 1999; accepted March 31, 1999.


*    References
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*References
 
1. Kerr JF, Wyllie AH, Currie AR. Apoptosis, a basic biological phenomenon with wide-ranging implications in tissue kinetics. Br J Cancer. 1972;26:239–257.[Medline] [Order article via Infotrieve]

2. Jacobson MD, Weil M, Raff MC. Programmed cell death in animal development. Cell. 1997;88:347–354.[Medline] [Order article via Infotrieve]

3. Nagata S. Apoptosis by death factor. Cell. 1997;88:355–365.[Medline] [Order article via Infotrieve]

4. Wyllie AH. Glucocorticoid-induced thymocyte apoptosis is associated with endogenous endonuclease activation. Nature. 1980;284:555–556.[Medline] [Order article via Infotrieve]

5. Cohen JJ. Programmed cell death in the immune system. Adv Immunol. 1991;50:55–85.[Medline] [Order article via Infotrieve]

6. Liu Y, Cigola E, Cheng W, Kajstura J, Olivetti G, Hintze TH, Anversa P. Myocyte nuclear mitotic division and programmed myocyte cell death characterize the cardiac myopathy induced by rapid ventricular pacing in dogs. Lab Invest. 1995;73:771–787.[Medline] [Order article via Infotrieve]

7. Sharov VG, Sabbah HN, Shimoyama H, Goussev AV, Lesch M, Goldstein S. Evidence of cardiocyte apoptosis in myocardium of dogs with chronic heart failure. Am J Pathol. 1996;148:141–149.[Abstract]

8. Teiger E, Than VD, Richard L, Wisnewsky C, Tea BS, Gadoury L, Tremblay J, Schwartz K, Hamet P. Apoptosis in pressure overload-induced heart hypertrophy in the rat. J Clin Invest. 1996;97:2891–2897.[Medline] [Order article via Infotrieve]

9. Li Z, Bing OH, Long X, Robinson KG, Lakatta EG. Increased cardiomyocyte apoptosis during the transition to heart failure in the spontaneously hypertensive rat. Am J Physiol. 1997;272:H2313–H2319.[Abstract/Free Full Text]

10. Packer M. The neurohormonal hypothesis: a theory to explain the mechanism of disease progression in heart failure [editorial]. J Am Coll Cardiol. 1992;20:248–254.[Abstract]

11. Francis GS, Chon JN, Johnson G, Rector TS, Goldman S, Simon A. Plasma norepinephrine, plasma renin activity, and congestive heart failure. relations to survival and the effects of therapy in V-HeFT II: the V-HeFT VA Cooperative Studies Group. Circulation. 1993;87(suppl VI):VI-40-VI-48.

12. Communal C, Singh K, Pimentel DR, Colucci WS. Norepinephrine stimulates apoptosis in adult rat ventricular myocytes by activation of the ß adrenergic pathway. Circulation. 1998;98:1329–1334.[Abstract/Free Full Text]

13. Zhong LT, Sarafian T, Kane DJ, Charles AC, Mah SP, Edwards RH, Bredesen DE. Bcl-2 inhibits death of central neural cells induced by multiple agents. Proc Natl Acad Sci U S A. 1993;90:4533–4537.[Abstract/Free Full Text]

14. Brune B, Hartzell P, Nicotera P, Orrenius S. Spermine prevents endonuclease activation and apoptosis in thymocytes. Exp Cell Res. 1991;195:323–329.[Medline] [Order article via Infotrieve]

15. Herskowitz A, Choi S, Ansari AA, Wesselingh S. Cytokine mRNA expression in postischemic/reperfused myocardium. Am J Pathol. 1995;146:419–428.[Abstract]

16. Levine B, Kalman J, Mayer L, Fillit HM, Packer M. Elevated circulating levels of tumor necrosis factor in severe chronic heart failure. N Engl J Med. 1990;323:236–241.[Abstract]

17. Yamada T, Matsumori A, Sasayama S. Therapeutic effect of anti-tumor necrosis factor-alpha antibody on the murine model of viral myocarditis induced by encephalomyocarditis virus. Circulation. 1994;89:846–851.[Abstract/Free Full Text]

18. Cheng W, Li B, Kajstura J, Li P, Wolin MS, Sonnenblick EH, Hintze TH, Olivetti G, Anversa P. Stretch-induced programmed myocyte cell death. J Clin Invest. 1995;96:2247–2259.

19. Krown KA, Page MT, Nguyen C, Zechner D, Gutierrez V, Comstock KL, Glembotski CC, Quintana PJE, Sabbadini RA. Tumor necrosis factor alpha-induced apoptosis in cardiac myocytes: involvement of the sphingolipid signaling cascade in cardiac cell death. J Clin Invest. 1996;98:2854–2865.[Medline] [Order article via Infotrieve]

20. Kirshenbaum LA, Moissac D. The bcl-2 gene product prevents programmed cell death of ventricular myocytes. Circulation. 1997;96:1580–1585.[Abstract/Free Full Text]

21. Long X, Boluyt MO, Hipolito ML, Lundberg MS, Zeng JS, O`Neill L, Cirielli C, Lakatta EG, Crow MT. p53 and the hypoxia-induced apoptosis of cultured neonatal rat cardiac myocytes. J Clin Invest. 1997;99:2635–2643.[Medline] [Order article via Infotrieve]

22. Hasegawa K, Meyers MB, Kitsis RN. Transcriptional coactivator p300 stimulates cell type-specific gene expression in cardiac myocytes. J Biol Chem. 1997;272:20049–20054.[Abstract/Free Full Text]

23. Hasegawa K, Fujiwara H, Itoh H, Nakao K, Fujiwara T, Imura H, Kawai C. Light and electron microscopic localization of brain natriuretic peptide in relation to atrial natriuretic peptide in porcine atrium: immunohistochemical study using specific monoclonal antibodies. Circulation. 1991;84:1203–1209.[Abstract/Free Full Text]

24. Hasegawa K, Fujiwara H, Doyama K, Miyamae M, Fujiwara T, Suga S, Mukoyama M, Nakao K, Imura H, Sasayama S. Ventricular expression of brain natriuretic peptide in hypertrophic cardiomyopathy. Circulation. 1993;88:372–380.[Abstract/Free Full Text]

25. Bishopric NH, Sato B, Webster KA. Beta-adrenergic regulation of a myocardial actin gene via a cyclic AMP-independent pathway. J Biol Chem. 1992;267:20932–20936.[Abstract/Free Full Text]

26. Dudley DT, Pang L, Decker SJ, Bridges AJ, Saltiel AR. A synthetic inhibitor of the mitogen-activated protein kinase cascade. Proc Natl Acad Sci U S A. 1995;92:7686–7689.[Abstract/Free Full Text]

27. Pang L, Sawada T, Decker SJ, Saltiel AR. Inhibitation of MAP kinase kinase blocks the differentiation of PC-12 cells induced by nerve growth factor. J Biol Chem. 1995;270:13585–13588.[Abstract/Free Full Text]

28. Sheng Z, Knowlton K, Chen J, Hoshijima M, Brown JH, Chien KR. Cardiotrophin 1 (CT-1) inhibition of cardiac myocyte apoptosis via a mitogen-activated protein kinase-dependent pathway. J Biol Chem. 1997;272:5783–5791.[Abstract/Free Full Text]

29. Parrizas M, Saltiel AR, LeRoith D. Insulin-like growth factor 1 inhibits apoptosis using the phosphatidylinositol 3'-kinase and mitogen-activated protein kinase pathways. J Biol Chem. 1997;272:154–161.[Abstract/Free Full Text]

30. Yao R, Cooper GM. Requirement for phosphatidylinositol-3 kinase in the prevention of apoptosis by nerve growth factor. Science. 1995;267:2003–2006.[Abstract/Free Full Text]

31. Liu Y, Kitsis RN. Induction of DNA synthesis and apoptosis in cardiac myocytes by E1A oncoprotein. J Cell Biol. 1996;133:325–334.[Abstract/Free Full Text]

32. Kirshenbaum LA, Schneider MD. Adenovirus E1A represses cardiac gene transcription and reactivates DNA synthesis in ventricular myocytes, via alternative pocket protein-and p300-binding domains. J Biol Chem. 1995;270:7791–7794.[Abstract/Free Full Text]

33. Geng Y-J, Ishikawa Y, Vatner DE, Wanger TE, Bishop SP, Vatner SF, Homcy CJ. Overexpression of Gs{alpha} accelerates programmed death (apoptosis) of myocardiocytes in transgenic mice. Circulation. 1996;94(suppl I):I-282. Abstract.

34. Arany Z, Newsome D, Oldread E, Livingston DM, Eckner R. A family of transcriptional adaptor proteins targeted by the E1A oncoprotein. Nature. 1995;374:81–84.[Medline] [Order article via Infotrieve]

35. Lundblad JR, Kwok RPS, Laurance ME, Harter ML, Goodman RH. Adenoviral E1A-associated protein p300 as a functional homologue of the transcriptional co-activator CBP. Nature. 1995;374:85–88.[Medline] [Order article via Infotrieve]




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