(Hypertension. 1998;31:50.)
© 1998 American Heart Association, Inc.
Scientific Contributions |
Cardiac Mitogen-Activated Protein Kinase Activities Are Chronically Increased in Stroke-Prone Hypertensive Rats
From the Department of Pharmacology, Osaka City University Medical School (Japan).
Correspondence to Shokei Kim, MD, Department of Pharmacology, Osaka City University Medical School, 1-4-54 Asahimachi, Abeno, Osaka 545, Japan.
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Abstract |
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Abstract—To examine chronic changes in mitogen-activated protein (MAP) kinases in cardiac hypertrophy, we determined the activities of two subfamilies of MAP kinases, including extracellular signal-regulated kinases (ERKs) and c-Jun NH2-terminal kinases (JNKs), in the heart of stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY) aged 5, 8, 14, and 24 weeks. MAP kinases were determined by using in-gel kinase assay. In both the left and right ventricles of WKY, the activities of ERKs (p44ERK and p42ERK) and JNKs (p46JNK and p55JNK) decreased significantly with age, indicating that aging remarkably downregulated cardiac MAP kinase activities. In SHRSP, left ventricular ERK and JNK activities were already significantly higher at the mild hypertensive phase than they were in the same age of WKY, and they remained higher until development of left ventricular hypertrophy. On the contrary, the right ventricle of SHRSP, which did not exhibit cardiac hypertrophy, had no significant increase in ERK or JNK activities compared with WKY, except for the slight increase in p55JNK in 24-week-old SHRSP. Antihypertensive treatment of SHRSP with imidapril, an angiotensin-converting enzyme inhibitor, decreased the left ventricular JNK activities (P<.01) but did not affect ERK activities, suggesting the contribution of hypertension or the renin-angiotensin system to the increase in JNKs. Our observations provide the first evidence that both ERK and JNK activities are higher in the left ventricle of SHRSP than WKY. However, further study is needed to elucidate the mechanism and the significance of the increased cardiac MAP kinases in SHRSP.
Key Words: extracellular signal-related kinase • hypertrophy • aging • in-gel kinase assay • c-Jun NH2–terminal kinase
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Introduction |
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Extracellular signal-regulated kinases belong to one subfamily of MAP kinases and are composed of 42- and 44-kD serine/threonine kinases (named p42ERK and p44ERK, respectively).1 ERKs are activated by various extracellular stimuli such as growth factors and tumor promoters and play a key role in cell growth and the regulation of various gene expressions.1 2 3 4 Furthermore, recent works on cultured cardiac myocytes5 6 7 8 9 10 11 support the idea that ERKs participate in the mechanism of cardiac hypertrophy.
JNKs, alternatively called the stress-activated protein kinases (SAPKs), recently have been identified as another subfamily of MAP kinases.12 13 14 15 16 Unlike ERKs, JNKs are preferentially activated by stress signals rather than by growth factors.15 16 Importantly, the activation of JNKs has been shown to be associated not only with cell growth and the regulation of gene expression but also with apoptosis,17 indicating the distinct biological function of JNKs from ERKs. Very recently, it has been postulated that JNKs are implicated in the pathophysiology of various cardiovascular diseases.18 19 Furthermore, quite recent work showed that JNKs in cultured cardiac myocytes are activated by hypertrophic stimuli such as stretch20 and angiotensin II,21 leading to the activation of the transcription factor, activator protein-1. However, little is known about the regulatory mechanism and pathophysiological role of these MAP kinases in vivo. Moreover, it remains to be determined whether the increase in MAP kinase activities in vivo occurs in hypertensive cardiac hypertrophy. Therefore, we determined the activities of cardiac ERKs and JNKs in SHRSP from the phase of prehypertension to the phase of established cardiac hypertrophy and compared them with those activities in WKY. We obtained the first evidence that aging significantly downregulates the activities of ERKs and JNKs and that the activities of both ERKs and JNKs are higher in the LV of SHRSP throughout the hypertensive phase.
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Methods |
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Experimental Protocol
All procedures were in accordance with institutional guidelines for animal research. Male SHRSP22 and WKY, purchased from Japan SLC, were fed standard laboratory chow (CE-2) and given tap water ad libitum. Blood pressure was measured by the tail-cuff method (TK-370A, Unicom Inc). SHRSP and WKY aged 5, 8, 14, and 24 weeks (each group, n=5 to 8) were killed by decapitation, the whole heart was rapidly excised and rinsed with cold saline, and the LV and RV were separated from the atria in precooled PBS (pH 7.4) containing 2.5 mmol/L EDTA, 2 mmol/L ß-glycerophosphate, 10 mmol/L NaF, 1 mmol/L sodium orthovanadate (Na3VO4), and 1 mmol/L PMSF. After being weighed, the LV and RV tissues were rapidly frozen in liquid nitrogen and stored at -80°C until protein extraction.
In the second experiments, we examined the effects of imidapril, an ACE inhibitor, on cardiac ERKs and JNKs of SHRSP. Imidapril23 (donated by Tanabe Seiyaku Co, Ltd) was suspended in 0.5% carboxymethyl cellulose. Ten-week-old SHRSP with mild hypertension were separated into two groups. One group of SHRSP (n=7) was given imidapril (10 mg/kg per day) orally by gastric gavage every morning for 21 days (from the age of 10 to 13 weeks), and the other group (n=7) was given vehicle in the same manner. Ten-week-old WKY (n=7) were treated with a vehicle in the same manner. Blood pressure was measured before and after the start of imidapril treatment. After 21 days of imidapril treatment, rats were killed by decapitation; the LV tissues were rapidly excised, frozen in liquid nitrogen, and stored at -80°C as described above.
Preparation of Cardiac Protein Extracts
For protein kinase assay, LV and RV tissues were
homogenized on ice with a polytron
homogenizer (PCU-11, kinematica AG) in a lysis buffer
(20 mmol/L HEPES [pH 7.2], 25 mmol/L NaCl, 2 mmol/L
EGTA, 0.2 mmol/L DTT, 60 µg/mL aprotinin, 2 µg/mL leupeptin,
1 mmol/L PMSF, 50 mmol/L NaF, 1 mmol/L
Na3VO4, 25 mmol/L
ß-glycerophosphate, and 0.1% Triton X-100). After incubation at
4°C for 30 minutes, the homogenates were sonicated
(Sonifier 250, Branson Ultrasonics Co) on ice for 1 minute and then
centrifuged at 10 000g at 4°C for 30 minutes. The
protein concentrations of the supernatants were measured with a protein
assay kit (Pierce) and stored at -80°C until use.
Measurement of Cardiac ERK Activities
The assay of ERK activities was performed by using the in-gel
kinase method.24 25 ERKs were determined as the
activity to phosphorylate myelin basic protein (MBP) as the
substrate. The samples of protein extracts (10 µg) from LV and RV,
prepared as described above, were boiled for 5 minutes in Laemmli’s
sample buffer26 (125 mmol/L Tris-HCl (pH
6.8), 4% SDS, 20% glycerol, 10% 2-mercaptoethanol, and 0.002%
bromophenol blue) containing 100 mmol/L
Na3VO4. The samples were
electrophoresed on SDS polyacrylamide (12%) gels polymerized
in the presence of 0.5 mg/mL of MBP. After electrophoresis, the gels
were incubated with 50 mmol/L Tris-HCl (pH 8.0) containing 20%
isopropanol at room temperature for 1 hour and then washed with 50
mmol/L Tris-HCl (pH 8.0) containing 5 mmol/L ß-mercaptoethanol
at room temperature for 1 hour. After denaturation with 50 mmol/L
Tris-HCl (pH 8.0) containing 6 mol/L guanidine-HCl and 5 mmol/L
ß-mercaptoethanol at room temperature for 1 hour, the kinases in the
gels were renatured by incubation in 50 mmol/L Tris-HCl (pH 8.0)
containing 0.04% Tween-40 and 5 mmol/L ß-mercaptoethanol at
4°C for 12 hours and equilibrated with kinase buffer (40 mmol/L
HEPES (pH 7.5), 0.1 mmol/L EGTA, 20 mmol/L
MgCl2 and 2 mmol/L DTT) for 1 hour. For the
kinase reaction, the gels were incubated in kinase buffer with 25
µmol/L ATP and 25 µCi [
-32P]ATP at
25°C for 1 hour. The reaction was terminated by immersing the gels in
5% trichloroacetic acid and 1% sodium pyrophosphate, followed by
extensive washing with the same solution several times. The gels then
were dried and subjected to autoradiography. To
estimate the incorporation of 32 P from
[-32P]ATP into MBP, the densities of
autoradiograms were analyzed with a bioimaging
analyzer (BAS-2000, Fuji Photo Film Co).
Measurement of Cardiac JNK Activities
The assay of JNK activities was performed by use of the in-gel
kinase method according to the techniques of Derijard et
al.13 JNK activities were estimated as the
ability to phosphorylate c-Jun as the substrate. We used
GST-c-Jun (1–79) protein as the substrate for JNKs. In brief, the
GST-c-Jun (1–79) plasmid, provided by Dr Masahiko Hibi (Osaka
University Medical School), was expressed as GST-fusion
protein27 in Escherichia
coli BL21 (DE3) (Novagen) by incubation with 0.4 mmol/L
isopropylthiogalactopyranoside at 28°C for 3 hours; the expressed
GST-c-Jun (1–79) protein was purified using glutathione-sepharose 4B
(Pharmacia Biotech Inc) according to the manufacturer’s
instructions.
Protein extracts (40 µg) from LV and RV were boiled for 5 minutes in Laemmli’s sample buffer containing 100 mmol/L Na3VO4 and then subjected to electrophoresis on SDS polyacrylamide (12%) gels containing 0.1 mg/mL of GST-c-Jun (1–79). After electrophoresis, the removal of SDS from the gels, the denaturation and subsequent renaturation of kinases in the gels, and the kinase reaction were carried out under the same conditions as the in-gel kinase assay of ERK described above. The kinase activity was analyzed with a bioimaging analyzer (BAS-2000).
Identification of ERKs and JNKs by Immunoprecipitation
To confirm that the activities of cardiac ERK and JNK can be
specifically measured by the in-gel kinase method, we performed in-gel
kinase assays after immunoprecipitation of cardiac extracts with their
specific antibodies. All antibodies used were purchased from Santa Cruz
Biotechnology, Inc (California) and were as follows: polyclonal rabbit
anti-p44ERK (ERK-1) immunoglobulin G (IgG) (c-16); polyclonal rabbit
anti-p42ERK (ERK-2) IgG (c-14); polyclonal rabbit anti-p46JNK (JNK-1)
IgG (c-17), which recognizes not only p46JNK but also p55JNK; and
polyclonal rabbit anti-p55JNK (JNK-2) IgG (FL). Cardiac extracts
containing 0.5 mg of protein were preabsorbed with 10 µL of
recombinant protein A-Agarose (50%, vol/vol) (Upstate Biotechnology,
Lake Placid, NY) at 4°C for 2 hours. After
centrifugation at 10 000g at 4°C for 15
minutes, the supernatants were incubated with 0.5 µg of each antibody
or normal rabbit IgG at 4°C for 2 hours and were added to 20 µL of
recombinant protein A-Agarose (50%, vol/vol), followed by incubation
at 4°C for 12 hours. After centrifugation at
800g for 10 minutes, the pellets were washed four times with
lysis buffer (20 mmol/L HEPES (pH 7.2), 25 mmol/L NaCl,
2 mmol/L EGTA, 50 mmol/L NaF, 1 mmol/L
Na3VO4, 1 mmol/L PMSF,
0.2 mmol/L DTT, 25 mmol/L ß-glycerophosphate, 60 µg/mL
aprotinin, 2 µg/mL leupeptin, and 0.1% Triton X-100) containing 0.5
mol/L NaCl. Finally, the pellets were suspended with 25 µL of lysis
buffer. The immunoprecipitates were boiled for 5 minutes in Laemmli’s
sample buffer containing 100 mmol/L
Na3VO4 and then
centrifuged, and the resulting supernatants were
electrophoresed on SDS-polyacrylamide (12%) gels containing
0.5 mg/mL of MBP or 0.1 mg/mL of GST-c-Jun (1–79) and subjected to
in-gel kinase assay of ERKs or JNKs as described above.
Furthermore, to demonstrate the validity of the quantification of ERKs and JNKs by in-gel kinase assay, various amounts of cardiac protein extracts (5, 10, and 20 µg for ERK and 20, 40, and 80 µg for JNK) were subjected to in-gel kinase assay as described above. The intensity of the bands was quantified by BAS-2000 and plotted against the amounts of protein extracts.
Statistical Analysis
All data are presented as mean±SEM. Statistical
significance was determined with two-way ANOVA, followed by the
least-squares means test. Differences were considered statistically
significant at a value of P<.05.
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Results |
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Age-Related Changes in Blood Pressure, Body Weight, LV Weight, and RV Weight
As shown in Fig 1A, blood pressure of SHRSP increased with age and reached 222±5 mm Hg at 24 weeks of age. At 5 weeks, there was no significant difference in blood pressure between WKY and SHRSP. At 8 weeks, however, blood pressure of SHRSP was already higher than that of WKY (P<.001). As shown in Fig 1B, body weight in both WKY and SHRSP gradually increased with age. Although no significant difference in body weight was found between WKY and SHRSP at 5 weeks, body weight of SHRSP was less than that of WKY throughout 8 to 24 weeks of age (P<.001). LV weight (corrected for body weight) of SHRSP decreased at 8 weeks of age compared with 5 weeks of age but was remarkably increased after 8 weeks (Fig 1C). On the other hand, LV weight (corrected for body weight) of WKY gradually decreased with age, supporting findings of our previous study.28 From 8 weeks of age, LV weight of SHRSP was significantly greater than that of WKY (P<.001; Fig 1C). In both WKY and SHRSP, RV weight (corrected for body weight) decreased with age, and that of 24-week-old WKY was slightly greater than that in SHRSP of the same age (P<.05; Fig 1D).
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). Each plot
represents mean±SEM (n=5 to 8). *P<.05,
**P<.01 vs age-matched WKY.
Identification of ERKs and JNKs
To identify cardiac ERKs or JNKs, we performed in-gel kinase
assays after immunoprecipitation of cardiac extracts with their
specific antibodies. As shown by in-gel kinase assay of ERKs in Fig 2A, five protein kinases corresponding to
molecular mass of 100 kD, 85 kD, 60 kD, 44 kD, and 42 kD were detected
in cardiac extracts not subjected to immunoprecipitation. In-gel kinase
assay after immunoprecipitation with anti-ERK antibodies confirmed that
the 44-kD kinase band corresponded to p44ERK (ERK-1) and the 42-kD
kinase band corresponded to p42ERK (ERK-2). As shown by in-gel kinase
assay of JNKs in Fig 2B, four protein kinases with molecular mass of 60
kD, 55 kD, 46 kD, and 44 kD were detected mainly in cardiac extracts
not subjected to immunoprecipitation. In-gel kinase assay after
immunoprecipitation with anti-JNK antibodies confirmed that the 46-kD
kinase band was p46JNK (JNK-1), and the 55-kD kinase band was p55JNK
(JNK-2). Thus, in the present study, the activities of ERKs (p44ERK
and p42ERK) and JNKs (p46JNK and p55JNK) in cardiac extracts could be
specifically measured by using in-gel kinase method.
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Furthermore, as shown in Fig 3, the correlation coefficients for standard curves of ERK and JNK by in-gel kinase assays were more than 0.99, indicating that the in-gel kinase assay used in this study allowed us to successfully quantify cardiac ERK and JNK activities.
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Age-Related Changes in LV ERK Activities
As shown by autoradiograms in Fig 4 in both WKY and SHRSP at all ages
examined, the relative proportion of p42ERK activity was larger than
that of p44ERK activity. LV p44ERK activity in WKY decreased remarkably
with age; p44ERK activity of 24-week-old WKY decreased to about 24% of
the p44ERK activity of 5-week-old WKY. At 5 weeks of age, p44ERK
activity in SHRSP already tended to be increased compared with WKY,
although that increase was not statistically significant. p44ERK
activity of SHRSP was significantly higher than that of WKY throughout
8 to 24 weeks of age (P<.05) (that of 24-week-old SHRSP was
2.2-fold higher than for the same age of WKY).
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Unlike p44ERK, LV p42ERK activity of WKY increased significantly at 8 weeks compared with p42ERK activity at 5 weeks (P<.01), but thereafter it decreased significantly with age; p42ERK activity of 24-week-old WKY decreased to 22% of the p42ERK activity of 5-week-old WKY. p42ERK activity in SHRSP was significantly higher than in WKY from 14 weeks of age and 2.4-fold higher at 24 weeks than in the same age of WKY.
Age-Related Changes in LV JNK Activities
As shown by autoradiograms in Fig 5, cardiac JNKs consisted of p46JNK and
p55JNK, which had similar relative proportions. As with p44ERK, LV
p46JNK activity in WKY decreased significantly with age; p46JNK
activity of 24-week-old WKY decreased to 11% of the p46JNK activity of
5-week-old WKY. In SHRSP, p46JNK activity increased significantly
compared with that of WKY (P<.05) during 8 to 24 weeks of
age. Unlike p46JNK, p55JNK activity in WKY did not significantly change
during 5 to 14 weeks but was remarkably decreased at 24 weeks; p55JNK
activity of 24-week-old WKY was 16% of the p55JNK activity of
5-week-old WKY. In 8- and 14-week-old SHRSP, p55JNK activity was 1.3-
and 1.4-fold higher, respectively, than for the same age of WKY.
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Age-Related Changes in RV ERKs and JNKs
As shown by autoradiograms in Fig 6, in the RV of both WKY and SHRSP, as in
the LV, the relative proportion of p42ERK activity was higher than
p44ERK activity. In the RV of WKY, p44ERK activity decreased remarkably
with aging and p42ERK activity was similar during 5 to 14 weeks but was
significantly reduced at 24 weeks, as in the case of the LV. p44ERK and
p42ERK activities of 8-week-old SHRSP were significantly lower than
those of the same age of WKY (P<.05). However, there was no
significant difference in p44ERK and p42ERK activities between both
strains at 5, 14, or 24 weeks.
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As shown in Fig 7, p46JNK activity in the RV of WKY was decreased with aging and p55JNK activity was decreased significantly only at 24 weeks (P<.05). These age-related changes in the RV of WKY were similar to those in the LV of WKY. No significant difference in p46JNK activity was found between WKY and SHRSP at all ages examined. p55JNK activity of SHRSP was significantly lower than in WKY at 8 weeks of age (P<.05) but was 1.4-fold higher at 24 weeks (P<.01).
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Effects of Imidapril on Cardiac ERK and JNK Activities in
SHRSP
As shown in the Table, 3 weeks of imidapril
treatment significantly decreased both blood pressure and LV weight of
SHRSP to levels similar to those of WKY. As shown in Fig 8, imidapril did not significantly reduce
LV p44ERK or p42ERK activities in SHRSP. Unlike ERKs, LV p46JNK and
p55JNK activities in imidapril-treated SHRSP were significantly
decreased (P<.01) compared with those activities in
vehicle-treated SHRSP, although they were significantly higher than
those of WKY (P<.05).
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Discussion |
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Various factors, including hemodynamic factors, humoral factors, and neural factors, are well known to be responsible for the pathophysiology of cardiac hypertrophy in a very complex manner.29 30 Pathological cardiac hypertrophy is characterized by myocyte growth, apoptosis,31 and significant changes in various cardiac performance-related gene expressions28 30 32 such as contractile proteins and extracellular matrix components. The first important mechanism underlying the pathological cardiac hypertrophy is the enhanced activation of signal transduction pathways, particularly the activation of protein kinases. MAP kinases, including ERKs and JNKs, are acknowledged to be one of the major protein kinases regulating cell growth and apoptosis, as well as various gene expressions.1 2 3 4 13 14 15 16 17 19 Previous studies on cultured cardiac myocytes in vitro show that ERKs are rapidly and transiently activated by various hypertrophic factors such as angiotensin II, endothelin-1,
1-adrenergic agonists,
phorbol esters, and mechanical stretch.5 6 7 8 9 Very
recent work investigating the effects of antisense
oligodeoxynucleotide directed against ERKs on
phenylephrine-induced hypertrophic response in cultured
rat cardiac myocytes demonstrates that ERKs are responsible for the
development of hypertrophy.10 All
these in vitro findings support the notion that ERKs play an important
role in the onset and development of cardiac hypertrophy,
which led us to examine ERKs in the heart of hypertensive rats in vivo.
The use of the in-gel kinase assay allowed us to successfully determine
the cardiac MAP kinases. In the present study, we found that the
increase in LV ERK activities in SHRSP compared with WKY continued from
the onset of hypertension to the establishment of cardiac
hypertrophy. This is in contrast to the in vitro data,
which show that the increase in ERK activities in cultured cardiac
myocytes by extracellular stimuli is not continuous but
transient.3 5 6 7 8 9 On the other hand, there was no
increase in ERK activities in the RV of SHRSP compared with WKY,
indicating that the increase in ERK activities of SHRSP was specific
for the LV. JNKs12 13 14 15 have been recently identified as another subfamily of MAP kinases and are shown to specifically activate c-Jun. JNKs are activated mainly by stress stimuli13 14 15 16 such as inflammatory cytokine, ultraviolet irradiation, heat shock, osmotic shock, and endotoxin, but unlike ERKs, JNKs are weakly activated by growth factors and phorbol esters and have different upstream cascades from ERKs. Very interestingly, in vitro studies on PC-12 pheochromocytoma cells demonstrate that JNKs are involved in apoptosis,17 opposing the growth-promoting effects of ERKs. Quite recent articles show that JNKs in cultured rat cardiac myocytes are activated by mechanical stretch20 and angiotensin II.21 Furthermore, JNKs also are activated in the isolated perfused rat heart by ischemia/reperfusion,18 in contrast to no activation of ERKs. Thus, JNKs are thought to play an important role in the development of cardiac disease in a different fashion from ERKs.19 However, the in vivo role of JNK in cardiac hypertrophy remains to be determined. Therefore, we also examined JNK activities in SHRSP.
In the present work, we showed that the increase in LV p46JNK and p55JNK activities already occurred in SHRSP with mild hypertension and continued to the development of hypertrophy, while the increase in JNK activities in SHRSP did not occur in nonhypertrophic RV except for p55JNK at 24 weeks of age. These observations suggest that the increased activities of JNKs may play some role in the development of LV hypertrophy in SHRSP.
To examine the mechanism of the increase in ERKs and JNKs in the LV of SHRSP, we treated SHRSP with imidapril. In the present study, imidapril not only normalized blood pressure of SHRSP but also reduced LV weight of SHRSP to similar levels to WKY. Of note, LV p44ERK or p42ERK activities in SHRSP were not decreased significantly by imidapril, supporting the idea that the increased ERK activities in SHRSP were not due to hypertension and might not contribute to the increased LV weight. On the other hand, LV p46JNK and p55JNK activities in SHRSP were decreased significantly by imidapril, indicating that the increased JNK activities of SHRSP are due to hypertension or the renin-angiotensin system, unlike ERKs. Thus, ERKs and JNKs are increased in SHRSP with a different mechanism.
Recently, we have examined the effects of age on the pattern of cardiac gene expressions in WKY rats and have found that aging itself significantly affects cardiac performance-related gene expression levels such as cardiac contractile proteins and extracellular matrix components.28 Furthermore, the age-related changes in cardiac gene expressions have been suggested to be implicated in the age-related disturbance of cardiac performance.33 In the present study, we have noted that aging remarkably decreased cardiac ERK and JNK activities of WKY. Our observations, together with the fact that ERKs and JNKs play an important role in the regulation of various gene expressions by activating transcription factors (Elk-1, c-jun, etc),1 2 3 5 14 16 suggest that the age-related changes in cardiac gene expressions are partially mediated by the diminished activity of cardiac ERKs and JNKs. However, further study is needed to demonstrate our assumption.
In conclusion, we first examined cardiac MAP kinase activities in hypertensive rats in vivo and obtained the first evidence that the activities of LV ERKs and JNKs were chronically increased in SHRSP. Moreover, the increased LV JNK activities in SHRSP appear to be mediated by hypertension or the renin-angiotensin system. However, our present work did not allow us to elucidate the mechanism of the enhanced LV ERK activities in SHRSP. It is also unclear whether our present data on MAP kinases in SHRSP can apply to other models of hypertensive rats, and whether the increase in ERK and JNK activities is due to cardiac myocytes, fibroblasts, or both. Thus, further in vivo study is needed to elucidate the mechanism and significance of the increase in cardiac MAP kinases in SHRSP.
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Acknowledgments |
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This work was supported in part by grants-in-aid for scientific research (05670100 and 09470527) from the Ministry of Education, Science, and Culture and by Osaka City University Medical Research Foundation Fund for Medical Research. The authors thank Dr Masahiko Hibi (Osaka University Medical School) for providing GST-c-Jun (1–79) plasmid. The authors are grateful to Eriko Gomi, Fumiko Arata, and Mami Motoi for their excellent technical assistance.
Received March 6, 1997; first decision March 22, 1997; accepted August 6, 1997.
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References |
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TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
1. Davis RJ. The mitogen-activated protein kinase signal transduction pathway. J Biol Chem. 1993;268:14553–14556.
2. Karin M. The regulation of AP-1 activity by
mitogen-activated protein kinases. J Biol Chem. 1995;270:16483–16486.
3. Nishida E, Gotoh Y. The MAP kinase cascade is essential for diverse signal transduction pathways. Trends Biochem Sci. 1993;18:128–131.[Medline] [Order article via Infotrieve]
4. Thomas G. MAP kinase by any other name smells just as sweet. Cell. 1992;68:3–6.[Medline] [Order article via Infotrieve]
5. Bogoyevitch MA, Andersson MB, Gillespie-Brown J, Clerk A, Glennon PE, Fuller SJ, Sugden PH. Adrenergic receptor stimulation of the mitogen-activated protein kinase cascade and cardiac hypertrophy. Biochem J. 1996;314:115–121.[Medline] [Order article via Infotrieve]
6. Bogoyevitch MA, Glennon PE, Sugden PH. Endothelin-1, phorbol esters and phenylephrine stimulate MAP kinase activities in ventricular cardiomyocytes. FEBS Lett. 1993;317:271–275.[Medline] [Order article via Infotrieve]
7. Sadoshima J, Jahn L, Takahashi T, Kulik T, Izumo S.
Molecular characteristics of the stress-induced adaptation of cultured
cardiac cells. J Biol Chem. 1992;267:10551–10560.
8. Sadoshima J, Izumo S. Mechanical stretch rapidly activates multiple signal transduction pathways in cardiac myocytes: potential involvement of an autocrine/paracrine mechanism. EMBO J. 1993;12:1681–1692.[Medline] [Order article via Infotrieve]
9. Yamazaki T, Tobe K, Hoh E, Maemura K, Kaida T, Komuro
I, Tamemoto H, Kadowaki T, Nagai R, Yazaki Y. Mechanical loading
activates mitogen-activated protein kinase and S6
peptide kinase in cultured rat cardiac myocytes. J Biol
Chem. 1993;268:12069–12076.
10. Glennon PE, Kaddoura S, Sale EM, Sale GJ, Fuller SJ,
Sugden PH. Depletion of mitogen-activated protein kinase using
an antisense oligodeoxynucleotide approach downregulates
the phenylephrine-induced hypertrophic response in rat
cardiac myocytes. Circ Res. 1996;78:954–961.
11. Kojima M, Shiojima I, Yamazaki T, Komuro I, Zou Z, Wang
Y, Mizuno T, Ueki K, Tobe K, Kadowaki T, Nagai R, Yazaki Y.
Angiotensin II receptor antagonist TCV-116
induces regression of hypertensive left ventricular
hypertrophy in vivo and inhibits the intracellular
signaling pathway of stretch-mediated cardiomyocyte
hypertrophy in vitro. Circulation. 1994;89:2204–2211.
12. Kyriakis JM, Avruch J. pp54 Microtubule-associated
protein 2 kinase. J Biol Chem. 1990;265:17355–17363.
13. Derijard B, Hibi M, Wu IH, Barrett T, Su B, Deng T, Karin M, Davis RJ. JNK1: a protein kinase stimulated by UV light and Ha-Ras that binds and phosphorylates the c-Jun activation domain. Cell. 1994;76:1025–1037.[Medline] [Order article via Infotrieve]
14. Kyriakis JM, Banerjee P, Nikolakaki E, Dai T, Rubie EA, Ahmad MF, Avruch J, Woodgett JR. The stress-activated protein kinase subfamily of c-Jun kinases. Nature. 1994;369:156–160.[Medline] [Order article via Infotrieve]
15. Davis RJ. MAPKs: new JNK expands the group. Trends Biochem Sci. 1994;19:470–473.[Medline] [Order article via Infotrieve]
16. Kyriakis JM, Avruch J. Sounding the alarm: protein
kinase cascades activated by stress and inflammation.
J Biol Chem. 1996;271:24313–24316.
17. Xia Z, Dickens M, Raingeaud J, Davis RJ, Greenberg ME.
Opposing effects of ERK and JNK-p38 MAP kinases on apoptosis.
Science. 1995;270:1326–1331.
18. Bogoyevitch MA, Gillespie-Brown J, Ketterman AJ, Fuller
SJ, Ben-Levy R, Ashworth A, Marshall CJ, Sugden PH. Stimulation of the
stress-activated mitogen-activated protein kinase
subfamilies in perfused heart. Circ Res. 1996;79:162–173.
19. Force T, Pombo CM, Avruch JA, Bonventre JV, Kyriakis
JM. Stress-activated protein kinases in
cardiovascular disease. Circ Res. 1996;78:947–953.
20. Komuro I, Kudo S, Yamazaki T, Zou Y, Shiojima I, Yazaki Y. Mechanical stretch activates the stress-activated protein kinases in cardiac myocytes. FASEB J. 1996;10:631–636.[Abstract]
21. Kudo S, Komuro I, Mizuno T, Yamazaki T, Zou Y, Shiojima
I, Takekoshi N, Yazaki Y. Angiotensin II stimulates c-Jun
NH2-terminal kinase in cultured cardiac myocytes of neonatal rats.
Circ Res. 1997;80:139–146.
22. Okamoto K, Yamori Y, Nagaoka A. Establishment of the stroke-prone spontaneously hypertensive rat (SHR). Circ Res. 1974;35(suppl I):I-143-I-153.
23. Kubo M, Kato J, Ochiai T, Ishida R. Pharmacological studies on (4S)-1-methyl-3-{(2S)-2-[N-((1S)-1-ethoxycarbonyl-3-phenylpropyl)-amino]propionyl}-2-oxo-imidazolidine-4-carboxylic acid hydrochloride(TA-6366), a new ACE inhibitor, I: ACE inhibitory and anti-hypertensive activities. Jpn J Pharmacol. 1990;53:201–210.[Medline] [Order article via Infotrieve]
24. Kameshita I, Fujisawa H. A sensitive method for the detection of calmodulin-dependent protein kinase II activity in sodium dodecyl sulfate-polyacrylamide gel. Anal Biochem. 1989;183:139–143.[Medline] [Order article via Infotrieve]
25. Gotoh Y, Nishida E, Yamashita T, Hoshi M, Kawakami M, Sakai H. Microtubule-associated-protein (MAP) kinase activated by nerve growth factor and epidermal growth factor in PC12 cells: identity with the mitogen-activated MAP kinase of fibroblastic cells. Eur J Biochem. 1990;193:661–669.[Medline] [Order article via Infotrieve]
26. Laemmi UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970;227:680–685.[Medline] [Order article via Infotrieve]
27. Smith DB, Johnson KS. Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene. 1988;67:31–40.[Medline] [Order article via Infotrieve]
28. Ohta K, Kim S, Iwao H. Role of
angiotensin-converting enzyme, adrenergic receptors, and
blood pressure in cardiac gene expression of spontaneously hypertensive
rats during development. Hypertension. 1996;28:627–634.
29. Morgan HE, Baker KM. Cardiac hypertrophy.
Mechanical, neural, and endocrine dependence. Circulation. 1991;83:13–25.
30. Schwartz K, Carrier L, Mercadier JJ, Lompre AM, Boheler KR. Molecular phenotype of the hypertrophied and failing myocardium. Circulation. 1993;87(suppl VII):VII-5-VII-10.
31. Teiger E, Than VD, Richard L, Wisnewsky C, Tea BS, Gaboury 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]
32. Kim S, Ohta K, Hamaguchi A, Yukimura T, Miura K, Iwao H. Effects of an AT1 receptor antagonist, an ACE inhibitor and a calcium channel antagonist on cardiac gene expressions in hypertensive rats. Br J Pharmacol. 1996;118:549–556.[Medline] [Order article via Infotrieve]
33. Takahashi T, Schunkert H, Isoyama S, Wei JY, Nadal-Ginard B, Grossman W, Izumo S. Age-related differences in the expression of proto-oncogene and contractile protein genes in response to pressure overload in the rat myocardium. J Clin Invest. 1992;89:939–946.[Medline] [Order article via Infotrieve]
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