Periodic Reporting for period 4 - BIOCARD (Deep BIOmodeling of human CARDiogenesis)
Reporting period: 2023-03-01 to 2024-02-29
To tackle these challenges, the BIOCARD project pursued three main objectives:
1) Enhance understanding of human CPC specification and differentiation mechanisms,
2) Investigate the role of human CPCs in different compartments of the heart through chimeric animal models, and
3) Develop advanced models of cardiac development and disease in the form of hiPSC-derived cardiac organoids and 3D engineered heart tissue.
By providing high-resolution analyses of human cardiogenesis, innovative platforms for investigating the fate and function of CPCs in vitro and ex utero, mechanistic insights into hypoplastic left heart syndrome (HLHS), and the first cardiac organoid imitating the molecular and functional patterning of the ventricular wall, it succeeded in breaking new ground in precise modeling of human heart development and disease.
In Objective 2, to facilitate the use of pigs in preclinical research, we performed an extensive anatomical and molecular characterization of porcine cardiogenesis based on native fetal hearts and cardiac cells derived from porcine expanded pluripotent stem cells (Rawat et al. Front. Cell Dev. Biol. 2023). We then generated porcine somatic cell donors lacking key cardiac regulators for the future generation of cardiogenesis-disabled porcine embryos through somatic cell nuclear transfer. Moreover, we successfully established CRISPR/Cas9 for somatic gene editing of pig hearts in vivo (Moretti et al. Nat. Med. 2020).
In Objective 3, we optimized the generation of 3D engineered myocardium based on native extracellular matrix (ECM) and used it to investigate HLHS phenotypes, demonstrating a significantly reduced contractile force and a failure of electromechanical maturation in constructs from patient hiPSCs compared to healthy controls (Krane et al. Circulation 2021, Lu et al. Theranostics 2021). Moreover, we successfully established the first self-organized cardiac organoid showing co-development of the myocardium and epicardium and imitating the molecular and functional patterning of the ventricular wall, which we called epicardioids (Meier et al. Nat. Biotechnol. 2023). We notably used epicardioids to gain insights into the fate trajectories of the human epicardial lineage and demonstrated their unique capacity to recapitulate congenital and stress-induced hypertrophy and fibrosis.