Cellular senescence machinery

Cellular senescence machinery refers to the integrated molecular pathways that mediate a state of permanent cell cycle arrest in response to various stressors, such as DNA damage, telomere shortening, or oncogene activation (He & Sharpless, 2017). This machinery is primarily governed by the p53/p21CIP1 and p16INK4a/Rb tumor suppressor pathways, which prevent the proliferation of potentially damaged cells (Gorgoulis et al., 2019). Beyond arrest, senescent cells develop a complex Senescence-Associated Secretory Phenotype (SASP), involving the secretion of pro-inflammatory cytokines, chemokines, and matrix metalloproteinases that can alter the local tissue microenvironment (Kirkland & Tchkonia, 2017). While senescence serves as a critical defense against cancer, the accumulation of senescent cells over time contributes to chronic inflammation and age-related pathologies (NIH, 2024). Therapeutic strategies targeting this machinery include senolytics, which selectively eliminate senescent cells by disrupting anti-apoptotic signaling (e.g., BCL-2 family proteins), and senomorphics, which modulate the SASP to mitigate its deleterious effects (Kirkland & Tchkonia, 2020). These interventions are currently being explored for a wide range of conditions, including idiopathic pulmonary fibrosis, osteoarthritis, and neurodegenerative diseases (Paez-Ribes et al., 2019). However, the heterogeneity of senescent cells and their beneficial roles in wound healing present significant challenges for drug development (Gorgoulis et al., 2019).

Other names

Cellular senescence pathwaySenescence-associated secretory phenotype (SASP) machinerySenescence-associated anti-apoptotic pathways (SCAPs)Senescence-associated regulatory network

Senolytic agents selectively induce apoptosis in senescent cells by inhibiting pro-survival pathways (e.g., BCL-2 family, PI3K/AKT, p53/p21/serpines), while senomorphic agents suppress the senescence-associated secretory phenotype (SASP) by inhibiting upstream signaling such as NF-κB, JAK/STAT, or mTOR (Kirkland & Tchkonia, 2020; NIH, 2024).