SSEA4-Positive Pig Induced Pluripotent Stem Cells Are Primed for Differentiation Into Neural Cells

Neural cells derived from induced pluripotent stem cells (iPSCs) have the potential for autologous cell therapies in treating patients with severe neurological disorders or injury. However, further study of efficacy and safety are needed in large animal preclinical models that have similar neural anatomy and physiology to humans such as the pig. The pig model for pluripotent stem cell therapy has been made possible for the first time with the development of pig iPSCs (piPSCs) capable of in vitro and in vivo differentiation into tissues of all three germ layers. Still, the question remains if piPSCs are capable of undergoing robust neural differentiation using a system similar to those being used with human iPSCs. In this study, we generated a new line of piPSCs from fibroblast cells that expressed pluripotency markers and were capable of embryoid body differentiation into all three germ layers. piPSCs demonstrated robust neural differentiation forming beta III-TUB/MAP2(+) neurons, GFAP(+) astrocytes, and O4(+) oligodendrocytes and demonstrated strong upregulation of neural cell genes representative of all three major neural lineages of the central nervous system. In the presence of motor neuron signaling factors, piPSC-derived neurons showed expression of transcription factors associated with motor neuron differentiation (HB9 and ISLET1). Our findings demonstrate that SSEA4 expression is required for piPSCs to differentiate into neurons, astrocytes, and oligodendrocytes and furthermore develop specific neuronal subtypes. This indicates that the pigs can fill the need for a powerful model to study autologous neural iPSC therapies in a system similar to humans.