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

Naturally occurring diseases in companion dogs such as cancer, immune-mediated and neuro-degenerative diseases 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 technology is still in its infancy and robust canine specific iPSC media formulations and differentiation protocols are lacking. Here, we have established NANOG-reporter canine iPSC (ciPSC) lines and found that FGF, activin/TGF beta, 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, basal medium, or extracellular matrix. These conditions allowed ciPSC lines to form a teratoma, including one line that could not form with the previous medium lacking these factors. Canine iPSCs cultured in the optimized medium showed the suppression of lineage-specific genes and 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 universal and robust culture condition provides a valuable resource to facilitate the utilization of ciPSCs for various studies, including the generation of canine translational models for human disease. Overall design: RNA-seq profiling of canine induced pluripotent stem cells cultured in either StemFit (control) or AR medium.