Stanford Cardiovascular Institute, Stanford University, Stanford, United States; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, United States
Carissa Lee
Stanford Cardiovascular Institute, Stanford University, Stanford, United States
Soah Lee
Department of Pharmacy, Sungkyunkwan University, Stanford, United States
Sharon Paige
Stanford Cardiovascular Institute, Stanford University, Stanford, United States; Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Stanford, United States
William Goodyer
Stanford Cardiovascular Institute, Stanford University, Stanford, United States; Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Stanford, United States
Sidra Xu
Stanford Cardiovascular Institute, Stanford University, Stanford, United States
Tahmina Samad
Stanford Cardiovascular Institute, Stanford University, Stanford, United States
Gabriela V Escobar
Stanford Cardiovascular Institute, Stanford University, Stanford, United States
Adrija Darsha
School of Medicine, University of California, San Diego, San Diego, United States
Aimee Beck
Stanford Cardiovascular Institute, Stanford University, Stanford, United States
Stanford Cardiovascular Institute, Stanford University, Stanford, United States; Department of Pediatrics, Stanford University, Stanford, United States
Stanford Cardiovascular Institute, Stanford University, Stanford, United States; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, United States; Division of Cardiovascular of Medicine, Department of Medicine, Stanford University, Stanford, United States
During mammalian development, the left and right ventricles arise from early populations of cardiac progenitors known as the first and second heart fields, respectively. While these populations have been extensively studied in non-human model systems, their identification and study in vivo human tissues have been limited due to the ethical and technical limitations of accessing gastrulation-stage human embryos. Human-induced pluripotent stem cells (hiPSCs) present an exciting alternative for modeling early human embryogenesis due to their well-established ability to differentiate into all embryonic germ layers. Here, we describe the development of a TBX5/MYL2 lineage tracing reporter system that allows for the identification of FHF- progenitors and their descendants including left ventricular cardiomyocytes. Furthermore, using single-cell RNA sequencing (scRNA-seq) with oligonucleotide-based sample multiplexing, we extensively profiled differentiating hiPSCs across 12 timepoints in two independent iPSC lines. Surprisingly, our reporter system and scRNA-seq analysis revealed a predominance of FHF differentiation using the small molecule Wnt-based 2D differentiation protocol. We compared this data with existing murine and 3D cardiac organoid scRNA-seq data and confirmed the dominance of left ventricular cardiomyocytes (>90%) in our hiPSC-derived progeny. Together, our work provides the scientific community with a powerful new genetic lineage tracing approach as well as a single-cell transcriptomic atlas of hiPSCs undergoing cardiac differentiation.
