Abstract 3660: Cardioprotective Effect of Eicosapentaenoic Acid, an Important Fish Oil, through Suppression of Endothelin-1-induced Cardiomyocyte Hypertrophy via PPAR-α
A growing body of evidences report the cardiovascular benefit of fish oil including eicosapentaenoic acid (EPA) in humans and experimental animals. While many studies link EPA to cardiac protection, the effect of EPA on endothelin (ET)-1-induced cardiomyocyte hypertrophy is unknown. On the other hand, the previous study demonstrated peroxisomal proliferator-activated receptor (PPAR) -α ligand (fenofibrate) prevents ET-1-induced cardiomyocyte hypertrophy. Though EPA is one of the lignads of PPAR-α, there was no study linking relationship between EPA and PPAR-α on hypertrophied cadiomyocyte. The present study investigated whether ET-1-induced cardiomyocyte hypertrophy could be prevented by the pre-treatment of EPA. Cardiomyocytes were accumulated from neonatal rat heart, cultured and at day 4 of culture, the cardiomyocytes were divided into three groups: control, ET-1 (0.1nM) treated and EPA-pre-treated (10μM) ET-1 groups. A 90% increase in cardiomyocyte surface area, a 75% increase in protein synthesis rate and an elevated actinin expression in cardiomyocyte were observed after ET-1 administration and these changes were greatly prevented by EPA pre-treatment. ET-1-induced hypertrophied cardiomyocytes showed a 2.3-fold and 2.1-fold increase in ANP and BNP mRNA expression, respectively, which were also suppressed by EPA pre-treatment. Pre-treatment of EPA could also attenuate phosphorylated JNK (an important component of MAPK cascade), c-Jun and PPAR-α in ET-1-induced hypertrophied cardiomyocytes. In conclusion, the present study showed that ET-1 can induce significant hypertrophic changes in cardiomyocytes with upregulation of important hypertrophic markers, and that this remodeling was effectively prevented by the pre-administration of EPA through suppressing PPAR-α, phosporylated JNK, and c-Jun.