Familial hypertrophic cardiomyopathy (HCM) is a genetic disease largely caused by a mutation in myosin binding protein C (MYBPC3) and it affects about 1:500 population leading to arrhythmic sudden death, heart failure, and atrial fibrillation. MYBPC3 activates calcium-induced actin-myosin filament sliding within the cardiac sarcomere, creating the force necessary for heart contraction. The underlying molecular mechanisms causing HCM phenotype remain elusive, therefore, there is an urgent need for a reliable in vitro human HCM model to investigate the pathogenesis of HCM. This study utilized isogenic human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with MYBPC3 gene mutation (wildtype, heterozygous, homozygous) and further micropatterned them into fiber-like structures on polyacrylamide hydrogels of physiological and fibrotic-like stiffnesses. Cells were cultured for an extended culture time up to 60 days and their morphology/attachment, contractility, and calcium transient were extensively and carefully evaluated. It was found that MYBPC3 knockout cells maintained the highest contraction amplitude, but had increased contraction, and relaxation durations, decreased calcium transient amplitude, as well as time to peak and decay times over the culture period in comparison to the isogenic wildtype. Overall, this study demonstrates that hiPSC-CMs can be successfully patterned and cultured for an extended time on hydrogels forming end-to-end connections, which can be served as a simple yet effective in vitro human model for studying mechanical dysfunction of HCM.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13539号 / 論医博第2279号 / 新制||医||1065(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 江藤 浩之, 教授 黒田 知宏, 教授 西浦 博 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM