Differentiation of Human Induced Pluripotent Stem Cells into Epicardial-Like Cells

The epicardium is a multipotent cell layer that is vital to myocardial development and regeneration. Epicardial cells contribute to cardiac fibroblast and smooth muscle populations of the heart and secrete paracrine factors that promote cardiomyocyte proliferation and angiogenesis. Despite a central role in cardiac biology, the mechanisms by which epicardial cells influence cardiac growth are largely unknown, and robust models of the epicardium are needed. Here, we review our protocol for differentiating induced pluripotent stem cells (iPSCs) into epicardial-like cells through temporal modulation of canonical Wnt signaling. iPSC-derived epicardial cells (iECs) resemble in vivo epicardial cells morphologically and display markers characteristic of the developing epicardium. We also review our protocol for differentiating iECs into fibroblasts and smooth muscle cells through treatment with bFGF and TGF-β1, respectively. iECs provide a platform for studying fundamental epicardial biology and can inform strategies for therapeutic heart regeneration.