LAUSR

ABSTRACT Dietary restriction (DR) has multiple and essential effects in protecting against DNA damage in model organisms. Persistent DNA damage plays a central role in the process of aging. Senescence‐associated secretory phenotype (SASP), as a product of cellular aging, can accelerate the process of cellular senescence as a feedback. In this study, we directly observed whether a DR of 30% for 6 months in aged rats could retard SASP by delaying the progression of DNA damage and also found the specific mechanism. The results revealed that a 30% DR could significantly improve renal pathology and some metabolic characteristics. The biomarkers and products of DNA damage were decreased in the process of renal aging on a 30% DR. A series of SASP, notably cytokine, chemokine, and growth factor, were obviously reduced by DR during renal aging. The phosphorylation levels of NF‐&kgr;B and I&kgr;B&agr; in aged kidneys of DR group were markedly reduced. These findings suggest that a 30% DR for 6 months can delay renal aging and reduce the accumulation of SASP by retarding the progression of DNA damage and decreasing the transcription activity of NF‐&kgr;B, thus providing a target to delay renal aging.