Robust derivation of epicardium and its differentiated smooth muscle cell progeny from human pluripotent stem cells

Abstract

The epicardium has emerged as a multipotent cardiovascular progenitor source with therapeutic potential for coronary smooth muscle cell, cardiac fibroblast (CF) and cardiomyocyte regeneration, owing to its fundamental role in heart development and its potential ability to initiate myocardial repair in injured adult tissues. Here, we describe a chemically defined method for generating epicardium and epicardium-derived smooth muscle cells (EPI-SMCs) and CFs from human pluripotent stem cells (HPSCs) through an intermediate lateral plate mesoderm (LM) stage. HPSCs were initially differentiated to LM in the presence of FGF2 and high levels of BMP4. The LM was robustly differentiated to an epicardial lineage by activation of WNT, BMP and retinoic acid signalling pathways. HPSC-derived epicardium displayed enhanced expression of epithelial- and epicardium-specific markers, exhibited morphological features comparable with human foetal epicardial explants and engrafted in the subepicardial space in vivo. The in vitro-derived epicardial cells underwent an epithelial-to-mesenchymal transition when treated with PDGF-BB and TGFβ1, resulting in vascular SMCs that displayed contractile ability in response to vasoconstrictors. Furthermore, the EPI-SMCs displayed low density lipoprotein uptake and effective lowering of lipoprotein levels upon treatment with statins, similar to primary human coronary artery SMCs. Cumulatively, these findings suggest that HPSC-derived epicardium and EPI-SMCs could serve as important tools for studying human cardiogenesis, and as a platform for vascular disease modelling and drug screening.

Modeling human somite development and fibrodysplasia ossificans progressiva with induced pluripotent stem cells

“…We also monitored key alternative cell fates (LPM and NCC) in the iPSC-derived PSM and SM states (), as these lineages are known to generate MSC-like cells under certain conditions. iPSC-derived LPM and NCC were acquired using previously published protocols (Iyer et al, 2015; Fukuta et al, 2014). The results showed that our induction methods preferentially lead iPSCs toward the paraxial mesoderm lineage, but not the LPM or NCC lineages.…”

Human fetal and adult epicardial-derived cells: a novel model to study their activation

“…Protocols have also been developed for the differentiation of EPDCs from human induced pluripotent stem (iPS) cells [46, 47]. However, since it is difficult to fully control the state of the iPS cell-derived EPDCs (fetal- or adult-like), they do not provide the opportunity to compare behavior of the developing and adult epicardium.…”

Targeting BMP signalling in cardiovascular disease and anaemia

“…82–84 Importantly, if BMP signalling persists for 3 days beyond when cardiac mesoderm is formed, cardiac progenitor cells differentiate into epicardial lineages instead of cardiomyocycytes. 85,86 The epicardium has been shown to serve as an important reservoir of cardiac fibroblasts and vascular smooth muscle progenitors in the developing heart, and plays an important role in cardiac repair after injury 87 . BMP signal transduction has been demonstrated in the atrioventricular canal, 88,89 and to a lesser extent in the cardiac crescent 88–90 using BMP reporter mice, which harbour a BMP responsive element that regulates the reporter genes lacZ or GFP .…”