Cardiac-specific deletion of mkk4 reveals its role in pathological hypertrophic remodeling but not in physiological cardiac growth.
Circ Res
; 104(7): 905-14, 2009 Apr 10.
Article
em En
| MEDLINE
| ID: mdl-19265040
ABSTRACT
Mitogen-activated protein kinase kinase (MKK)4 is a critical member of the mitogen-activated protein kinase family. It is able to activate the c-Jun NH(2)-terminal protein kinase (JNK) and p38 mitogen-activated protein kinase in response to environmental stresses. JNK and p38 are strongly implicated in pathological cardiac hypertrophy and heart failure; however, the regulatory mechanism whereby the upstream kinase MKK4 activates these signaling cascades in the heart is unknown. To elucidate the biological function of MKK4, we generated mice with a cardiac myocyte-specific deletion of mkk4 (MKK4(cko) mice). In response to pressure overload or chronic beta-adrenergic stimulation, upregulated NFAT (nuclear factor of activated T-cell) transcriptional activity associated with exacerbated cardiac hypertrophy and the appearance of apoptotic cardiomyocytes were observed in MKK4(cko) mice. However, when subjected to swimming exercise, MKK4(cko) mice displayed a similar level of physiological cardiac hypertrophy compared to controls (MKK4(f/f)). In addition, we also discovered that MKK4 expression was significantly reduced in heart failure patients. In conclusion, this study demonstrates for the first time that MKK4 is a key mediator which prevents the transition from an adaptive response to maladaptive cardiac hypertrophy likely involving the regulation of the NFAT signaling pathway.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
Cardiomegalia
/
MAP Quinase Quinase 4
/
Coração
/
Insuficiência Cardíaca
/
Miocárdio
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article