Identification and characterization of POSTN

Background: The meniscus exhibits a limited intrinsic self-repair capacity, particularly in its avascular inner region. A major obstacle in developing regenerative therapies is the lack of understanding at the cellular or molecular level regarding its repair and regeneration. This study aimed to characterize the critical cellular population that drives the meniscal healing process. Methods: We performed single-cell RNA sequencing (scRNA-seq) on human clinical meniscus samples and established a meniscal injury model in New Zealand white rabbits for parallel analysis. Computational analyses, including pseudotime trajectory inference, were conducted to delineate cellular states and transitions. To dynamically trace cell fate, lineage tracing was employed. Functional validation was achieved through the isolation, genetic manipulation, and transplantation of the candidate progenitor cells into injury models in Results: scRNA-seq revealed that a population of synovium-derived fibroblasts, characterised by high periostin expression, represents a unique injury-responsive population. Upon meniscal injury, these cells proliferated and rapidly migrated to the lesion site. Both pseudotime analysis and lineage tracing confirmed that this population transitioned into a chondrogenic state during the later stages of meniscal healing, showing progenitor characteristics; hence, they were termed POSTN Conclusion: This study identifies POSTN The translational potential of this article: Our findings suggest that the recruitment or transplantation of POSTN