Signaling pathway-based culture condition improves differentiation potential of canine induced pluripotent stem cells

Naturally occurring diseases in companion dogs are increasingly being recognized as valuable translational disease models. While induced pluripotent stem cell (iPSC) technology had revolutionized the field of human bio-medical research, canine iPSC (ciPSC) technology is still in its infancy, and robust canine-specific iPSC medium formulations and differentiation protocols are lacking. Here, we have established NANOG-reporter ciPSC lines and found that fibroblast growth factor (FGF), activin/transforming growth factor (TGF)-β, and WNT signals were critical for the robust maintenance of ciPSCs. Manipulating these signaling pathways stabilized the culture of ciPSC regardless of the cell line or basal medium. ciPSCs cultured in the optimized medium showed a homogenized global gene expression pattern. Furthermore, the ciPSCs cultured in this medium successfully differentiated into cardiomyocytes displaying homogenous contraction as well as sarcomere alignment. This robust culture condition provides a valuable resource to facilitate the utilization of ciPSCs for various studies, including human disease modeling.