Insights into Suture Stem Cells: Distributions, Characteristics, and Applications

Stem cells play an indispensable part in bone formation, homeostasis, and regeneration. The origin of skeletal stem cells (SSCs) in long bones has been extensively discussed, and the major cell population is considered to reside in the perivascular niche of the bone marrow. Cranial bones are distinct from long bones in both the origins of their cell lineage and the manner of osteogenesis. Recently, multiple tissue-resident craniofacial stem cell populations have been identified, among which cranial suture-derived stem cells, known as suture mesenchymal stem cells (SuSCs), exhibit unique biological characteristics. Whether SuSCs have potential therapeutic uses to repair cranial bone defects and alleviate congenital skeletal diseases, represented mainly by craniosynostosis, is a question of great research value. This review focuses on craniofacial stem cells, especially SuSCs, with the goal of summarizing the latest progress as well as giving insight into their regulatory molecular mechanisms and potential therapeutic targets.