Skeletal stem cells (SSCs) and related progenitors with osteogenic potential, collectively termed skeletal stem and/or progenitor cells (SSPCs), are crucial for providing osteoblasts for bone formation during homeostatic tissue turnover and fracture repair. Besides mediating normal bone physiology, they also have important roles in various metabolic bone diseases, including osteoporosis. SSPCs are of tremendous interest because they represent prime future targets for osteoanabolic therapies and bone regenerative medicine. Remarkable progress has been made in characterizing various SSC and SSPC populations in postnatal bone. SSPCs exist in the periosteum and within the bone marrow stroma, including subsets localizing around arteriolar and sinusoidal blood vessels; they can display osteogenic, chondrogenic, adipogenic and/or fibroblastic potential, and exert critical haematopoiesis-supportive functions. However, much remains to be clarified. By the current markers, bona fide SSCs are commonly contained within broader SSPC populations characterized by considerable heterogeneity and overlap, whose common versus specific functions in health and disease have not been fully unravelled. Here, we review the present knowledge of the identity, fates and relationships of SSPC populations in the postnatal bone environment, their contributions to bone maintenance, the changes observed upon ageing, and the effect of metabolic diseases such as osteoporosis and diabetes mellitus.

骨骼干细胞 （SSC） 和具有成骨潜力的相关祖细胞，统称为骨骼干和/或祖细胞 （SSPC），对于在稳态组织更新和骨折修复过程中为骨骼形成提供成骨细胞至关重要。除了介导正常的骨骼生理学外，它们在包括骨质疏松症在内的各种代谢性骨病中也起着重要作用。SSPC 具有极大的兴趣，因为它们代表了骨合成代谢疗法和骨再生医学的主要未来靶点。在表征出生后骨骼中各种 SSC 和 SSPC 群体方面取得了显着进展。SSPC 存在于骨膜和骨髓基质内，包括位于小动脉和肝窦血管周围的亚群;它们可以显示成骨、成软骨、成脂肪和/或成纤维细胞的潜力，并发挥关键的造血支持功能。然而，还有很多事情有待澄清。根据目前的标志物，真正的 SSC 通常包含在更广泛的 SSPC 人群中，这些人群的特点是相当大的异质性和重叠性，其在健康和疾病中的共同功能与特定功能尚未完全解开。在这里，我们回顾了目前关于出生后骨骼环境中 SSPC 群体的身份、命运和关系的知识，它们对骨骼维护的贡献，衰老时观察到的变化，以及骨质疏松症和糖尿病等代谢疾病的影响。