TY - JOUR
T1 - Effect of electrical modification of cardiomyocytes on transcriptional activity through 5′-AMP-activated protein kinase
AU - Kakinuma, Yoshihiko
AU - Zhang, Yanan
AU - Ando, Motonori
AU - Sugiura, Tetsuro
AU - Sato, Takayuki
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/11
Y1 - 2004/11
N2 - Endothelin-1 (ET-1) is known as an aggravating factor of the failing cardiomyocytes and, therefore, a therapeutic method is indispensable to decrease cardiac ET-1 expression. To study the mechanisms of how cardiac ET-1 gene expression can be modified, we investigated the effect of electrical stimulation against cardiomyocytes. Considering the physiology of cardiomyocytes, in vitro cultured cardiomyocytes demonstrate distinctive features from in vivo cardiomyocytes (i.e. the absence of a stretch along with electrical stimulation). In this study, we especially focused on the effect of electrical stimulation. The electrical stimulation reduced the gene expression of ET-1 mRNA in rat primary cultured cardiomyocytes. Furthermore, this effect on the transcriptional modification of ET-1 was also identified in H9c2 cells. Luciferase activity using H9c2 cells was decreased by electrical stimulation in the early phase, suggesting that the attenuation of the ET-1 gene transcription by electrical stimulation should be due to a transcriptional repression. To further investigate a trigger signal involved in the transcriptional repression, phosphorylation of 5′-AMP-activated protein kinase (AMPK) was evaluated. It was revealed that AMPK was phosphorylated in the early phase of electrical stimulation of H9c2 cells as well as in rat primary cultured cardiomyocytes, and that AMPK phosphorylation was followed by ET-1 transcriptional repression, suggesting that electrical stimulation directly regulates AMPK. This study suggests that AMPK activation in cardiomyocytes plays a crucial role in the transcriptional repression of ET-1.
AB - Endothelin-1 (ET-1) is known as an aggravating factor of the failing cardiomyocytes and, therefore, a therapeutic method is indispensable to decrease cardiac ET-1 expression. To study the mechanisms of how cardiac ET-1 gene expression can be modified, we investigated the effect of electrical stimulation against cardiomyocytes. Considering the physiology of cardiomyocytes, in vitro cultured cardiomyocytes demonstrate distinctive features from in vivo cardiomyocytes (i.e. the absence of a stretch along with electrical stimulation). In this study, we especially focused on the effect of electrical stimulation. The electrical stimulation reduced the gene expression of ET-1 mRNA in rat primary cultured cardiomyocytes. Furthermore, this effect on the transcriptional modification of ET-1 was also identified in H9c2 cells. Luciferase activity using H9c2 cells was decreased by electrical stimulation in the early phase, suggesting that the attenuation of the ET-1 gene transcription by electrical stimulation should be due to a transcriptional repression. To further investigate a trigger signal involved in the transcriptional repression, phosphorylation of 5′-AMP-activated protein kinase (AMPK) was evaluated. It was revealed that AMPK was phosphorylated in the early phase of electrical stimulation of H9c2 cells as well as in rat primary cultured cardiomyocytes, and that AMPK phosphorylation was followed by ET-1 transcriptional repression, suggesting that electrical stimulation directly regulates AMPK. This study suggests that AMPK activation in cardiomyocytes plays a crucial role in the transcriptional repression of ET-1.
KW - 5′-AMP-activated protein kinase
KW - Cardiomyocytes
KW - Endothelin-1
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U2 - 10.1097/01.fjc.0000166318.91623.f9
DO - 10.1097/01.fjc.0000166318.91623.f9
M3 - Article
C2 - 15838342
AN - SCOPUS:11144330211
VL - 44
SP - S435-S438
JO - Journal of Cardiovascular Pharmacology
JF - Journal of Cardiovascular Pharmacology
SN - 0160-2446
IS - SUPPL. 1
ER -