Understanding and targeting senescence in kidney disease.

Kidney disease affects >850 million people worldwide and remains a major contributor to patient morbidity, mortality, and healthcare burden. Despite advances in renoprotective therapies, current treatments are largely focused on managing risk factors such as hypertension, hyperfiltration, and hyperglycaemia, with limited options to modify disease progression at the cellular level. Emerging evidence suggests that cellular senescence, a state of irreversible cell-cycle arrest accompanied by chronic pro-inflammatory signalling, plays a significant role in chronic kidney disease (CKD) pathogenesis, particularly within tubular epithelial cells (TECs). Senescent TECs accumulate in injured kidneys, driving inflammation, fibrosis, and loss of regenerative capacity. This process is triggered by diverse stressors, including ischaemia-reperfusion injury, metabolic stress, and uremic toxin exposure. The recognition of senescence as a pathological and potentially modifiable process has opened new therapeutic avenues in nephrology. Preclinical studies demonstrate that senolytics, which selectively eliminate senescent cells, and senomorphics, which suppress the harmful senescence-associated secretory phenotype (SASP), can reduce renal fibrosis and preserve kidney function in experimental models of fibrosis in the kidney and other organs. Translating these approaches into clinical practice requires overcoming key challenges, including the lack of validated non-invasive biomarkers to monitor renal senescence and the heterogeneity of senescent cells across different disease stages. This review discusses the contribution of cellular senescence to kidney ageing and disease progression and outlines the underlying molecular mechanisms and biomarkers of renal senescence. It also highlights recent advances in senotherapeutic strategies, emphasizing future directions for integrating senescence-targeted therapies into comprehensive CKD management.