Matrix-dependent cardiac progenitor cell fate is instructed by the early regulation of YAP and Plk2

Although recent studies support regenerative potential based on cardiac progenitor cells (CPCs), it remains unclear what cues regulate CPC fate. Using 2- and 3D-culture models, we demonstrate that the two most abundantly expressed matrix proteins in the heart, laminin and fibronectin, have opposite roles in CPC fate decision. CPCs on fibronectin showed predominantly nuclear localization of the transcriptional co-activator YAP and maintained proliferation. In contrast, seeding on laminin induced cytosolic retention and degradation of YAP and altered gene expression, which preceded decreased proliferation and enhanced lineage commitment. RNA-sequencing identified Plk2 as candidate target gene of YAP. Plk2 expression depended on YAP stability, was rapidly downregulated on laminin, and its regulation was sufficient to rescue and/or mimic the CPC response to laminin and fibronectin, respectively. These findings propose a novel role of Plk2 and identify an early molecular mechanism in matrix-instructed CPC fate with potential implications for therapeutic cardiac regeneration.