ROS accelerates the progression of hypertrophic cardiomyopathy.

MYBPC3 mutations are the leading cause of hypertrophic cardiomyopathy. Here, to study the pathogenesis of hypertrophic cardiomyopathy, we created a MYBPC3 knockout (KO) model using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). MYBPC3-deleted hiPSC-CMs revealed the characteristics of heart failure, which exhibited increased contractility at 30 days but decreased at 40 days. Furthermore, at 40 days, it also shows abnormal calcium handling, increased ROS levels, and mitochondrial damage. Further RNA sequencing revealed that the oxidative stress pathway was aberrant, in addition to alterations linked to hypertrophic cardiomyopathy. Moreover, after adding melatonin to hiPSC-CMs at 30 days, MYBPC3-deleted hiPSC-CMs showed restored calcium handling capacity, decreased ROS levels, and improved myocardial contractility. In summary, reducing ROS can improve the phenotype of hypertrophic cardiomyopathy.