Yifei Miao#, Lei Tian#, Marcy Martin, Sharon L. Paige, Francisco X. Galdos, Jibiao Li, Alyssa Klein, Hao Zhang, Ning Ma, Yuning Wei, Maria Stewart, Soah Lee, Jan-Renier Moonen, Bing Zhang, Paul Grossfeld, Seema Mital, David Chitayat, Joseph C. Wu, Marlene Rabinovitch, Timothy J. Nelson, Shuyi Nie, Sean M. Wu, Mingxia Gu. Single-Cell Transcriptomic Analysis Reveals Developmentally Impaired Endocardial Population in Hypoplastic Left Heart Syndrome.

#These authors contributed equally

Contact person: Mingxia Gu, Mingxia.Gu@cchmc.org

Hypoplastic left heart syndrome (HLHS) is a fatal single ventricle malformation which results in severe underdevelopment of left ventricle, mitral valve, aortic valve, and ascending aorta. Previously, mechanistic studies focused on intrinsic defects in cardiomyocytes. However, this does not sufficiently explain the abnormal development of cardiac valve and vasculature, which are known to originate from endocardium. Thus, we aim to identify the underlying transcriptomic and functional abnormalities attributed to various endocardial and endothelial subtypes, and to determine new therapeutic targets. We generated induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) from HLHS patient and age-matched control and applied single cell RNA-seq (scRNA-seq) to reveal EC heterogeneity, differentially expressed genes, and altered signaling transductions. iPSCs were firstly treated with Wnt activator to induce mesoderm generation, then incubated with EC differentiation medium including VEGF and FGF growth factors. After 8-10 days differentiation, iPSC-ECs were purified with CD144 microbeads-based MACS sorting and applied to 10X chromium 3’ single-cell RNA-seq platform (V2 version). Chromium Single Cell Software Suite v2.1.1was used for pre-processing the single cell RNA-seq data. Endocardial and endothelial populations were both captured within the 1482 cells from control and 896 cells from HLHS iPSC-ECs.