Abstract 278: Dual Modulation of Microscale Tissue Engineering and Energy Metabolism for Maturation of Human Pluripotent Stem Cell-Derived Cardiomyocytes

Background: Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent a viable cell source for clinical application and other purposes, such as disease modeling and drug discovery for cardiovascular diseases. However, their immature phenotype limits their utility for these applications. It is widely known that the transition from fetal to adult heart during development is accompanied by an alteration in energy metabolism from glycolysis to fatty acid oxidation (FAO), respectively. Using this metabolic hallmark of cardiomyocyte maturation, we investigated a platform that combines three-dimensional (3D) cell cultivation and molecules that target key pathways involved in the energy metabolism of cardiomyocytes. Methods: Cardiac spheres of highly-enriched hPSC-CMs were generated from cardiac-differentiated cultures and treated with a combination of five molecules or control (DMSO) for one week. We used functional, morphological, transcriptome and metabolome analyses to assess the maturation status of hPSC-CMs. RESULTS: Treatment of 3D hPSC-CMs with a combination of five molecules elicited increased FAO along with mitochondrial respiratory capacity. These changes in oxidative capacity were associated with increased mitochondrial content and DNA. In addition, cardiac spheres treated with combined molecules displayed enhanced calcium transient kinetics when compared to control cells. RNA sequencing revealed upregulation of genes involved in many cellular metabolic processes, including FAO. Lastly, metabolic profiling of these cardiac spheres identified more than one hundred metabolites that were altered upon treatment. Conclusions: Our study showed that microscale tissue engineering along with treatment of hPSC-CMs with a combination of five molecules increase mitochondrial function, alter molecular and metabolic profiles, and potentially improve cardiomyocyte maturation.