Atrial natriuretic peptide inhibits cardiomyocyte hypertrophy through mitogen-activated protein kinase phosphatase-1.
Cardiac hypertrophy is formed in response to hemodynamic overload. Although a variety of factors such as catecholamines, angiotensin II (AngII), and endothelin-1 (ET-1) have been reported to induce cardiac hypertrophy, little is known regarding the factors that inhibit the development of cardiac hypertrophy. Production of atrial natriuretic peptide (ANP) is increased in the hypertrophied heart and ANP has recently been reported to inhibit the growth of various cell types. We therefore examined whether ANP inhibits the development of cardiac hypertrophy. Pretreatment of cultured cardiomyocytes with ANP inhibited the AngII- or ET-1-induced increase in the cell size and the protein synthesis. ANP also inhibited the AngII- or ET-1-induced hypertrophic responses such as activation of mitogen-activated protein kinase (MAPK) and induction of immediate early response genes and fetal type genes. To determine how ANP inhibits cardiomyocyte hypertrophy, we examined the mechanism of ANP-induced suppression of the MAPK activation. ANP strongly induced expression of MAPK phosphatase-1 (MKP-1) and overexpression of MKP-1 inhibited AngII- or ET-1-induced hypertrophic responses. These growth-inhibitory actions of ANP were mimicked by a cyclic GMP analog 8-bromo-cyclic GMP. Taken together, ANP directly inhibits the growth factor-induced cardiomyocyte hypertrophy at least partly via induction of MKP-1. Our present study suggests that the formation of cardiac hypertrophy is regulated not only by positive but by negative factors in response to hemodynamic load.
Department of Cardiovascular Medicine, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Doubun
D
Hayashi
Sumiyo
S
Kudoh
Ichiro
I
Shiojima
Yunzeng
Y
Zou
Koichiro
K
Harada
Masaki
M
Shimoyama
Yasushi
Y
Imai
Koshiro
K
Monzen
Tsutomu
T
Yamazaki
Yoshio
Y
Yazaki
Ryozo
R
Nagai
Issei
I
Komuro
D000818:Animals; D000831:Animals, Newborn; D009320:Atrial Natriuretic Factor / Q000378:metabolism* / Q000494:pharmacology*; D006332:Cardiomegaly / Q000378:metabolism* / Q000473:pathology; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D054638:Dual Specificity Phosphatase 1; D017874:Immediate-Early Proteins / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects*
D018797:Cell Cycle Proteins; D017874:Immediate-Early Proteins; D009320:Atrial Natriuretic Factor; D020928:Mitogen-Activated Protein Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D054638:Dual Specificity Phosphatase 1; C517021:Dusp1 protein, rat; D017027:Protein Tyrosine Phosphatases