Discovery of a chemical small molecule inducing umbilical cord mesenchymal stem cell differentiation to vascular endothelial cells

Abstract Human umbilical cord mesenchymal stem cells (hUC-MSCs) have emerged as promising candidates for clinical applications in vascular disease therapy and in the in vitro modeling of vascular regeneration. However, the translational potential of hUC-MSCs requires direct differentiation into functional vascular lineage cells, particularly vascular endothelial cells (VECs) and endothelial progenitor cells (EPCs). A critical challenge is the lack of reliable sources that yield sufficient quantities of mature VECs/EPCs for therapeutic purposes. To address this limitation, we established an efficient protocol for generating VECs from hUC-MSCs. Preconditioning hUC-MSCs using small molecules with cytoprotective properties can enhance their potential for use in cell-based therapeutics. Through systematic screening, we identified CPP as a novel small chemical molecule that effectively induces the endothelial differentiation of hUC-MSCs. Remarkably, our CPP-based induction protocol achieved > 90% conversion to functionally competent VECs within 5 days, as evidenced by both in vitro assays and in vivo functional validation. Single-cell RNA sequencing (scRNA-seq) analysis further delineated the differentiation trajectory and confirmed the acquisition of endothelial-specific molecular signatures during lineage commitment. These findings establish CPP as a potent inducer of rapid endothelial differentiation, and provide mechanistic insights into stem cell fate determination. Graphical Abstract Take home figure CPP drives the differentiation of human umbilical cord mesenchymal stem cells (hUC-MSCs) into functionally competent vascular endothelial cells (VECs). Crucially, the long non-coding RNA MEG3 acts as a pivotal regulator within this differentiation pathway.