High p16? senescence load confers increased responsiveness to senolytic therapy in aged female mice
Aging is accompanied by the accumulation of senescent cells, which contributes to tissue dysfunction and chronic inflammation. However, the burden of senescent cells and the efficacy of their clearance may differ between sexes, which is a critical yet understudied aspect of geroscience. Here, we combined transcriptomic, proteomic, and functional analyses to investigate sex-specific accumulation and removal of p16? senescent cells during aging. Using single-nucleus and bulk RNA-seq, senescence-specific GLF16 staining, and bioluminescence imaging, we showed that aged female mice accumulated a higher burden of p16? cells across multiple tissues, particularly the liver. Targeted elimination of p16? cells via ganciclovir (GCV) in the p16-3MR mouse model resulted in significant improvements in physical performance, liver function, and skin regeneration in females but not in males. Multi-omics profiling revealed that p16? cell clearance in females reprograms liver tissue toward a more youthful state, characterized by the upregulation of mitochondrial pathways and downregulation of immune and inflammatory signatures. These molecular changes closely mirror those induced by established longevity interventions such as calorie restriction, rapamycin, and acarbose. Moreover, integrative analysis across independent senescence-targeting studies identified a core set of conserved transcriptional regulators and gene targets, including Srm, Cd36, and Lrrfip1, which are involved in mitochondrial health and immune modulation. Together, our findings highlight the sex-specific benefit of senescent cell clearance in aging and provide mechanistic insight into the rejuvenating effects of targeting p16? cells, supporting their potential as therapeutic targets in age-related diseases. Overall design: RNA-Seq profiling of liver samples from p16-3MR and wild type female and male mice treated with ganciclovir (GCV) or vehicle. 3 biological replicates per group.