Abstract Bone morphogenetic protein-4 (BMP4) is a member of the bone morphogenetic protein family which plays an important role in bone formation, inflammation and cardiac hypertrophy. The aim of this study was to investigate the underlying molecular mechanism that BMP4-induced cardiomyocyte hypertrophy. H9c2 cells were used to measure cell surface area and protein synthesis. Western blot was used to examine hypertrophic marker brain natriuretic peptide (BNP) protein expression and phosphorylation of ERK1/2. The results exhibited that cell surface area, protein synthesis and BNP protein expression were increased with BMP4 treatment. While PD98059 inhibited these effects of BMP4. In addition, BMP4 treatment increased phosphorylation of ERK1/2 in a time- and dose-dependent manner. PD98059 treatment decreased phosphorylation of ERK1/2 that was increased by BMP4. These results suggest that BMP4 induces cardiomyocyte hypertrophy through the activation of ERK1/2 cell signaling pathway.
ABSTRACT Odanacatib (ODN) is a selective inhibitor of cathepsin K. The cysteine protease cathepsin K has been implicated in cardiac hypertrophy. Resistine is an adipokine which is identified to promote cardiac hypertrophy. Here, we hypothesize that ODN mitigates resistin-induced myocyte hypertrophy. Cell surface area and protein synthesis were measured after treatment with resistin and ODN in H9c2 cells. The expression of cardiomyocyte hypertrophy marker BNP and β-MHC was detected by RT-qPCR. The expression and phosphorylation of AMPK and LKB1 were analyzed with Western blot. Resistin could significantly increase cardiomyocyte cell surface area, protein synthesis, and embryonic gene BNP and β-MHC expression, inhibit phosphorylation of AMPK and LKB1. ODN could significantly reverse the effects of resistin. Collectively, our data suggest that ODN can inhibit cardiomyocyte hypertrophy induced by resistin and the underlying mechanism may be involved in LKB1/AMPK pathway.