A single-donor proof-of-concept single-cell analysis maps heterogeneous differentiation trajectories toward cartilage-like states in human urine-derived stem cells

• Urine-derived stem cells (USCs) can undergo chondrogenic differentiation, but single-cell analysis reveals heterogeneous transcriptional trajectories and limited similarity to mature cartilage. • A candidate transient epithelial-like state marked by CDH1 expression was identified along the differentiation trajectory, suggesting a potential intermediate stage. • Mapping to a cartilage reference atlas showed low overall confidence (median score 0.34), with only a minority of cells (7.8% overall, 17.6% induced) confidently resembling articular cartilage states. • The study underscores the need for cautious interpretation of USC chondrogenesis and highlights the importance of single-cell resolution for understanding differentiation heterogeneity.