Cellular senescence, first observed and defined through cell culture studies, is a cell fate associated with essentially permanent cell cycle arrest and that can be triggered by a variety of inducers. Emerging evidence suggests senescence is a dynamic process with diverse functional characteristics. Depending on the tissue, type of inducer, and time since induction, senescent cells can promote tissue repair and re-modeling, prevent tumor development, or contribute to age-related disorders and chronic diseases, including cancers. Senescent cell characteristics appear to depend on multiple factors and be influenced by the milieu and other senescent cells locally and at a distance. We review diverse phenotypes of senescent cells originating from different cell types, senescence inducers over time since induction of senescence, and across conditions and diseases. This background is essential to inform further understanding about senescent cell subtypes and will point towards rational senescence-modulating strategies for achieving therapeutic benefit.

细胞衰老首先通过细胞培养研究观察和定义，是一种与基本上永久的细胞周期停滞相关的细胞命运，可以由多种诱导剂触发。新出现的证据表明，衰老是一个具有多种功能特征的动态过程。根据组织、诱导剂的类型和诱导后的时间，衰老细胞可以促进组织修复和重塑，防止肿瘤发展，或导致与年龄相关的疾病和慢性疾病，包括癌症。衰老细胞特征似乎取决于多种因素并受环境影响以及局部和远处的其他衰老细胞。我们回顾了源自不同细胞类型的衰老细胞的不同表型，自诱导衰老以来随时间推移的衰老诱导剂，以及跨条件和疾病。这一背景对于进一步了解衰老细胞亚型至关重要，并将指出合理的衰老调节策略以实现治疗益处。