TAK733 attenuates adrenergic receptor-mediated cardiomyocyte hypertrophy via inhibiting ErkThr188 phosphorylation.

Cardiac hypertrophy is an important risk factor for heart failure. The MEK-ERK axis has been reported as a major regulator in controlling cardiac hypertrophy. TAK733 is a potent and selective MEK inhibitor that suppresses cell growth in a broad range of cell lines. Therefore, we aimed to investigate the anti-hypertrophic effect of TAK733 in cardiomyocytes. Cardiomyocyte hypertrophy was induced with norepinephrine (NE) or phenylepinephrine (PE) using H9c2 cells. To confirm the cardiomyocyte hypertrophy, cell size and protein synthesis were measured and hypertrophy-related gene expression was estimated by reverse transcription polymerase chain reaction. To identify the signaling pathway involved, immunoblot analysis were performed. We observed that NE activated MEK-ERK signaling and increased ANP and BNP expression, resulting in cardiomyocyte hypertrophy. TAK733 significantly reduced cardiomyocyte hypertrophy by regulating NE-induced ERK1/2 and ERKThr188 activation, hypertrophy marker expression, and cardiomyocyte hypertrophy through depression of MEK activity. In addition, we examined that PE-induced cardiomyocyte hypertrophy was also attenuated by TAK733. Here, we report that TAK733 suppressed NE- or PE-induced cardiomyocyte hypertrophy by repressing a crucial component of cardiac hypertrophy-related pathways. These results suggest that TAK733 may be a useful therapeutics for cardiac hypertrophy and warrants further in vivo studies.