[Research progress in the identification and lineage differentiation of skeletal stem cell]

Skeletal system contains various stem cell niches in which the self-renewal and differentiation of different kinds of stem cells are supported. Stem cell-based therapy has been applicated variedly. The skeletal stem cells (SSC), which are mesenchyme-derived and skeletal-lineage committed progenitors, can be found in the skeletal system. They are able to self-renew and colone both in vivo and in vitro. SSC have the potential of multi-directional differentiation to cartilage, bone, adipocytes and marrow stroma. Several types of SSC have been identified based on lineage tracing and single-cell RNA sequencing technique. Compared to mesenchymal stem cells, SSC are groups of less heterogeneous cells with accurate surface marker and identifiable biological behavior. Thus, clarifying the properties of SSC might provide new insight for stem cell therapy. In this article, the authors retrieved and reviewed SSC researches mainly focusing on the identification, spatio-temporal distribution and functional characteristics of SSC. The application of scRNA-seq in skeletal stem cell identification and functional study was also discussed.