Historically, cellular senescence has been viewed as an irreversible cell-cycle arrest process with distinctive phenotypic alterations that were implicated primarily in aging and tumor suppression. Recent discoveries suggest that cellular senescence represents a series of diverse, dynamic, and heterogeneous cellular states with the senescence-associated secretory phenotype (SASP). Although senescent cells typically contribute to aging and age-related diseases, accumulating evidence has shown that they also have important physiological functions during embryonic development, late pubertal bone growth cessation, and adulthood tissue remodeling. Here, we review the recent research on cellular senescence and SASP, highlighting the key pathways that mediate senescence cell-cycle arrest and initiate SASP. We also summarize recent literature on the role of cellular senescence in maintaining bone homeostasis and mediating age-associated osteoporosis, discussing both the beneficial and adverse roles of cellular senescence in bone during different physiological stages, including bone development, childhood bone growth, adulthood bone remodeling, and bone aging.

中文翻译：

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关于好与坏的故事：骨稳态和疾病中的细胞衰老。

从历史上看，细胞衰老一直被认为是不可逆的细胞周期停滞过程，具有明显的表型改变，主要涉及衰老和肿瘤抑制。最近的发现表明，细胞衰老代表了一系列具有衰老相关分泌表型（SASP）的多样，动态和异质细胞状态。尽管衰老细胞通常会导致衰老和与年龄有关的疾病，但越来越多的证据表明，它们在胚胎发育，青春期晚期骨骼发育停止和成年组织重塑期间也具有重要的生理功能。在这里，我们回顾了有关细胞衰老和SASP的最新研究，重点介绍了介导衰老细胞周期停滞和启动SASP的关键途径。