Discovery of zerumbone as a new agent for cardiac hypertrophy by high-throughput screening using human embryonic stem cell-derived cardiomyocytes

Abstract:

Background: Pathological cardiac hypertrophy is considered an adaptive response of the heart due to cardiovascular diseases such as hypertension, aortic and valvular stenosis, and inherited cardiomyopathy caused by mutations in sarcomeric proteins. It is a risk factor of various forms of cardiovascular diseases and closely associated with heart failure. Current medications for cardiac hypertrophy are limited and often only target the symptoms without a radical effect. There is a strong demand for developing new drugs to improve the overall treatment. Methods: We firstly established a hypertrophy model of human embryonic stem cell (hESC)-derived cardiomyocytes by norepinephrine treatment. Using high-throughput drug screening a library of small-molecule natural products and high-content analyses of hESC-cardiomyocyte size, we identified zerumbone as an effective new agent alleviating concentric cardiac hypertrophy. The downstream molecular pathway induced by zerumbone was identified by RNA-seq analyses of zerumbone treated hESC-cardiomyocytes and confirmed by biochemical studies.Results: We found that zerumbone not only inhibited norepinephrine-induced hypertrophy of hESC-derived human cardiomyocytes in vitro, but also alleviated cardiac hypertrophy in spontaneous hypertensive rats and Mybpc3-G790A hypertrophic cardiomyopathy mice invivo. This inhibition of cardiac hypertrophy by zerumbone was not dependent on lowering blood pressure. We further found that zerumbone markedly activated the NRF2/HO-1 related signaling pathway which showed a cardioprotective effect on cardiac hypertrophy. Zerumbone directly bound to and induced high molecular weight KEAP1, which impeded the interaction of CUL3 with KEAP1, leading to the inhibition of NRF2 ubiquitination and NRF2 accumulation and translocation into the nucleus. Inhibition of HO-1 expression blocked the effect of zerumbone in attenuating cardiomyocyte hypertrophy. Conclusion: Our data indicate that zerumbone is an effective small molecule alleviating pathological cardiac hypertrophy. It could be used in combination with current antihypertensive drugs for hypertension patients with cardiac hypertrophy and may also be used for patients of inherited hypertrophic cardiomyopathy.