Abstract P2121: Modeling Genetic Dilated Cardiomyopathies With Engineered Heart Tissues From Patient-derived And Isogenic Mutant Induced Pluripotent Stem Cells

The availability of human induced pluripotent stem cells (hiPSCs) has offered the possibility to study human-derived models of different genetic strata of cardiomyopathy for mechanistic discovery and therapeutic development. However, the phenotypes derived from cardiomyocytes differentiated from hiPSCs in conventional 2-dimensional culture systems often fail to reproducibly model clinical presentations, thereby reducing the translatability of readouts from these assays. Here we report 3-dimensional engineered heart tissues (EHTs) produced with a variety of cell lines harboring patient-derived mutations (TTN, RBM20, BAG3) known to cause dilated cardiomyopathy (DCM) which recapitulate contractile deficits associated with DCM. Internal development of EHTs also recapitulate contractile defects with small interfering RNA (siRNA) knockdown models of haploinsufficiency across multiple disease states. These observed findings with EHTs suggests improved maturity in cardiomyocytes through the presentation of microenvironmental cues akin to those seen in vivo . With continued advances in EHT technologies and capabilities, this platform may serve to significantly reduce drug candidate attrition, as well as provide new insights into pathology, prototyping of therapeutic approaches, and mechanism of action that were previously difficult to obtain.

Abstract P436: Modeling Genetic Dilated Cardiomyopathy Using Induced Pluripotent Stem Cell-derived Engineered Heart Tissues For Precision Medicine

Recent advancement of human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) technologies has opened the door to next-generation modeling of human cardiac biology and disease. Not only does this alleviate the need for human primary tissue and compensate for the well documented deficiencies of rodent models for cardiovascular disease, but these technologies may lead to the identification of better candidates for clinical development. Unfortunately, most current 2D hiPSC-CM models lack the biochemical, mechanical, and electrical feedback that cardiomyocytes endure in a multi-cellular aligned tissue, which limits their translatability into clinical settings. To address this, we incorporated hiPSC-CMs modeling various genetic dilated cardiomyopathies (DCM) into 3D engineered heart tissues (EHTs). Here, we show these models develop distinguishable contractile defects recapitulating hallmarks of DCM when compared to biologically relevant controls. Moreover, this distinct phenotype is quantitative, reproducible, and demonstrates utility for drug discovery. As this innovative technology continues to develop, EHTs are on the forefront of emerging biomimetic assays that can be used to prevent drug attrition in the late stages of drug development.