close
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1998 Jun;18(6):3518-26.
doi: 10.1128/MCB.18.6.3518.

Opposing effects of Jun kinase and p38 mitogen-activated protein kinases on cardiomyocyte hypertrophy

S Nemoto  1 , Z Sheng, A Lin
Affiliations

Opposing effects of Jun kinase and p38 mitogen-activated protein kinases on cardiomyocyte hypertrophy

S Nemoto et al. Mol Cell Biol. 1998 Jun.

Abstract

c-Jun N-terminal protein kinase (JNK) and p38, two distinct members of the mitogen-activated protein (MAP) kinase family, regulate gene expression in response to various extracellular stimuli, yet their physiological functions are not completely understood. In this report we show that JNK and p38 exerted opposing effects on the development of myocyte hypertrophy, which is an adaptive physiological process characterized by expression of embryonic genes and unique morphological changes. In rat neonatal ventricular myocytes, both JNK and p38 were stimulated by hypertrophic agonists like endothelin-1, phenylephrine, and leukemia inhibitory factor. Expression of MAP kinase kinase 6b (EE), a constitutive activator of p38, stimulated the expression of atrial natriuretic factor (ANF), which is a genetic marker of in vivo cardiac hypertrophy. Activation of p38 was required for ANF expression induced by the hypertrophic agonists. Furthermore, a specific p38 inhibitor, SB202190, significantly changed hypertrophic morphology induced by the agonists. Surprisingly, activation of JNK led to inhibition of ANF expression induced by MEK kinase 1 (MEKK1) and the hypertrophic agonists. MEKK1-induced ANF expression was also negatively regulated by expression of c-Jun. Our results demonstrate that p38 mediates, but JNK suppresses, the development of myocyte hypertrophy.

PubMed Disclaimer

Figures

FIG. 1
FIG. 1
Activation of p38, JNK, and ERK in myocytes. (A) Myocytes were grown in serum-free medium for 24 h and then treated with ET-1 (10 nM) or PE (50 μM) for the indicated times or left untreated. The cells were harvested after stimulation, and whole-cell extracts were prepared. Endogenous p38 was immunoprecipitated from cell extracts (30 μg) with anti-p38 antibody, and its activity was measured in immune complex kinase assays with GST-ATF2 (2 μg) as a substrate. (B) Endogenous JNK was immunoprecipitated from cell extracts (30 μg) with anti-JNK1 antibody, and its activity was measured in immune complex kinase assays with GST–c-Jun (2 μg) as a substrate. (C) Endogenous ERK was immunoprecipitated from cell extracts (30 μg) with anti-ERK antibody, and its activity was measured in immune complex kinase assays with MBP (4 μg) as a substrate. For all panels, fold stimulation is indicated below each lane.
FIG. 2
FIG. 2
Activation of p38 stimulates gene transcription in myocytes. (A) Myocytes were cotransfected with a 5×GAL4-Luc reporter plasmid (1 μg/plate) and expression vectors encoding p38, MKK6b, and/or MKK6b(EE) (300 ng each) and/or GAL4-Elk or GAL4-Elk(Ala383/389) (10 ng each) in the presence (+) or absence of the specific p38 inhibitor SB202190 (20 μM) as indicated. After 48 h, cells were harvested, and luciferase activity was determined and normalized to the protein content of each extract. Luciferase activity expressed by cells transfected with pSRα was given an arbitrary value of 1. The results are presented as means ± standard errors (error bars) and represent six individual experiments. (B) Myocytes were transfected with expression vectors encoding MKK6b, M2-Flag-tagged p38, or empty vector (3 μg each) as indicated. M2-p38 was immunoprecipitated with anti-M2 antibody (Kodak Inc.), and its activity was measured as described in the legend to Fig. 1A.
FIG. 3
FIG. 3
Activation of p38 by itself is sufficient to stimulate ANF expression in myocytes. Myocytes were cotransfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding p38, p38(Y→F), MKK6b, and/or MKK6b(EE) (300 ng each), in the presence (+) or absence of the specific p38 inhibitor SB202190 (20 μM) as indicated. After 48 h, the cells were harvested and luciferase activity was determined and normalized to the protein content of each extract. Luciferase activity expressed by cells transfected with pSRα was given an arbitrary value of 1. The results are presented as means ± standard errors (error bars) and represent six individual experiments.
FIG. 4
FIG. 4
p38 mediates the stimulatory effects of ET-1, PE, and LIF on ANF expression in myocytes. Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding p38 and MKK6b (300 ng each). The cells were treated with hypertrophic agonists ET-1 (10 nM) (A), PE (50 μM) (B), or LIF (1 nM) (C), in the presence (+) or absence of the specific p38 inhibitor SB202190 (20 μM), as indicated. The ANF-Luc activity was determined as described in the legend to Fig. 3. The results are presented as means ± standard errors (error bars) and represent six individual experiments.
FIG. 4
FIG. 4
p38 mediates the stimulatory effects of ET-1, PE, and LIF on ANF expression in myocytes. Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding p38 and MKK6b (300 ng each). The cells were treated with hypertrophic agonists ET-1 (10 nM) (A), PE (50 μM) (B), or LIF (1 nM) (C), in the presence (+) or absence of the specific p38 inhibitor SB202190 (20 μM), as indicated. The ANF-Luc activity was determined as described in the legend to Fig. 3. The results are presented as means ± standard errors (error bars) and represent six individual experiments.
FIG. 4
FIG. 4
p38 mediates the stimulatory effects of ET-1, PE, and LIF on ANF expression in myocytes. Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding p38 and MKK6b (300 ng each). The cells were treated with hypertrophic agonists ET-1 (10 nM) (A), PE (50 μM) (B), or LIF (1 nM) (C), in the presence (+) or absence of the specific p38 inhibitor SB202190 (20 μM), as indicated. The ANF-Luc activity was determined as described in the legend to Fig. 3. The results are presented as means ± standard errors (error bars) and represent six individual experiments.
FIG. 5
FIG. 5
Inhibition of p38 activity changes the hypertrophic morphology induced by ET-1 and LIF in myocytes. Myocytes were either left untreated (A to C) or were treated with ET-1 (10 nM) (D to F) or LIF (1 nM) (G to I), in the presence or absence (−) of the specific MEK1 inhibitor PD098059 (50 μM) (B, E, and H) or the specific p38 inhibitor SB202190 (10 μM) (C, F, and I), as indicated. After 48 h, the cells were stained with anti-α-MHC monoclonal antibody, followed by fluorescein isothiocyanate-conjugated anti-mouse immunoglobulin (green). ANF polyclonal antibody was recognized by rhodamine-conjugated anti-rabbit immunoglobulin G (orange).
FIG. 6
FIG. 6
Stimulation of c-Jun transcription activity by MEKK1 in myocytes is through the JNK pathway. Myocytes were transfected with the 5×GAL4-Luc reporter plasmid (1 μg/plate), GAL4–c-Jun or GAL4–c-Jun(Ala63/73) (10 ng each), and expression vector encoding MEKKΔ (10 ng) or JNK1 or JNK1 (APF) (amounts as shown) as indicated. The GAL4-Luc activity was determined as described in the legend to Fig. 2. The results are presented as means ± standard errors (error bars) and represent six individual experiments, except that the data on 300 ng of JNK1 represent three individual experiments.
FIG. 7
FIG. 7
Activation of JNK inhibits MEKK1-induced ANF expression. (A) Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vector encoding MEKKΔ (10 ng) or JNK1 or JNK1 (APF) (amounts as shown) as indicated. (B) Myocytes were transfected with an ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding MEKKΔ (10 ng) and/or JNKK1 or JNKK1 (AA) (amounts as shown) as indicated. The results are presented as means ± standard errors (error bars) and represent six individual experiments. (C) Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding MEKKΔ (10 ng) and/or c-Jun or c-Jun (A63) (amounts as shown), or empty vector as indicated. The results are presented as means ± standard errors (error bars) and represent three individual experiments. For all panels, the ANF-Luc activity was measured as described in the legend to Fig. 3.
FIG. 7
FIG. 7
Activation of JNK inhibits MEKK1-induced ANF expression. (A) Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vector encoding MEKKΔ (10 ng) or JNK1 or JNK1 (APF) (amounts as shown) as indicated. (B) Myocytes were transfected with an ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding MEKKΔ (10 ng) and/or JNKK1 or JNKK1 (AA) (amounts as shown) as indicated. The results are presented as means ± standard errors (error bars) and represent six individual experiments. (C) Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding MEKKΔ (10 ng) and/or c-Jun or c-Jun (A63) (amounts as shown), or empty vector as indicated. The results are presented as means ± standard errors (error bars) and represent three individual experiments. For all panels, the ANF-Luc activity was measured as described in the legend to Fig. 3.
FIG. 7
FIG. 7
Activation of JNK inhibits MEKK1-induced ANF expression. (A) Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vector encoding MEKKΔ (10 ng) or JNK1 or JNK1 (APF) (amounts as shown) as indicated. (B) Myocytes were transfected with an ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding MEKKΔ (10 ng) and/or JNKK1 or JNKK1 (AA) (amounts as shown) as indicated. The results are presented as means ± standard errors (error bars) and represent six individual experiments. (C) Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding MEKKΔ (10 ng) and/or c-Jun or c-Jun (A63) (amounts as shown), or empty vector as indicated. The results are presented as means ± standard errors (error bars) and represent three individual experiments. For all panels, the ANF-Luc activity was measured as described in the legend to Fig. 3.
FIG. 8
FIG. 8
Activation of JNK inhibits ANF expression induced by ET-1, PE, and LIF. Myocytes were transfected with the ANF-Luc reporter plasmid (1.5 μg/plate) and expression vectors encoding JNK1 or JNK1 (APF) (150 ng each). The cells were left untreated or were treated with the hypertrophic agonists as indicated. The ANF-Luc activity was measured as described in the legend to Fig. 3. The results are presented as means ± standard errors (error bars) and represent six individual experiments.
See this image and copyright information in PMC

References

    1. Anversa P, Beghi C, Kikkawa Y, Olivetti G. Myocardial response to infarction in the rat. Morphometric measurement of infarct size and myocyte cellular hypertrophy. Am J Pathol. 1985;118:484–492. - PMC - PubMed
    1. Bogoyevitch M A, Gillespie-Brown J, Ketterman A J, Fuller S J, Ben-Levy R, Ashworth A, Marshall C J, Sugden P H. Stimulation of the stress-activated mitogen-activated protein kinase subfamilies in perfused heart. p38/RK mitogen-activated protein kinases and c-Jun N-terminal kinases are activated by ischemia/reperfusion. Circ Res. 1996;79:162–173. - PubMed
    1. Bogoyevitch M A, Glennon P E, Andersson M B, Clerk A, Lazou A, Marshall C J, Parker P J, Sugden P H. Endothelin-1 and fibroblast growth factors stimulate the mitogen-activated protein kinase signaling cascade in cardiac myocytes. The potential role of the cascade in the integration of two signaling pathways leading to myocyte hypertrophy. J Biol Chem. 1994;269:1110–1119. - PubMed
    1. Boulton T G, Yancopoulos G D, Gregory J S, Slaughter C, Moomaw C, Hsu J, Cobb M H. An insulin-stimulated protein kinase similar to yeast kinases involved in cell cycle control. Science. 1990;249:64–65. - PubMed
    1. Chen R-H, Sarnecki C, Blenis J. Nuclear localization and regulation of erk- and rsk-encoded protein kinases. Mol Cell Biol. 1992;12:915–927. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources