Dihydroartemisinin eliminates senescent cells by promoting autophagy-dependent ferroptosis via AMPK/mTOR signaling pathway.

Cellular senescence is an irreversible cell-cycle arrest in response to a variety of cellular stresses, which contribute to the pathogenesis of a variety of age-related degenerative diseases. However, effective antisenescence strategies are still lacking. Drugs that selectively target senescent cells represent an intriguing therapeutic strategy to delay aging and age-related diseases. Thus, we thought to investigate the effects of dihydroartemisinin (DHA) on senescent cells and elucidated its mechanisms underlying aging. Stress-induced premature senescence (SIPS) model was built in NIH3T3 cells using H2O2 and evaluated by ß-galactosidase staining. Cells were exposed to DHA and subjected to cellular activity assays including viability, ferroptosis, and autophagy. The number of microtubule-associated protein light-chain 3 puncta was detected by immunofluorescence staining. The iron content was assessed by spectrophotometer and intracellular reactive oxygen species (ROS) was measured by fluorescent probe dichlorodihydrofluorescein diacetate. We found that DHA triggered senescent cell death via ferroptosis. DHA accelerated ferritin degradation via promoting autophagy, increasing the iron contents, promoting ROS accumulation, thus leading to ferroptotic cell death in SIPS cells. In addition, autophagy inhibitor BafA1 preconditioning inhibited ferroptosis induced by DHA. Moreover, Atg5 silencing and autophagy inhibitor BafA1 preconditioning inhibited ferroptosis induced by DHA. We also revealed that the expression of p-AMP-activated protein kinase (AMPK) and p-mammalian target of rapamycin (mTOR) in senescent cells was downregulated. These results suggested that DHA may be a promising drug candidate for clearing senescent cells by inducing autophagy-dependent ferroptosis via AMPK/mTOR signaling pathway.

Cordycepin inhibits cell senescence by ameliorating lysosomal dysfunction and inducing autophagy through the AMPK and mTOR-p70S6K pathway.

Cell senescence is closely related to autophagy. In this article, we identified a natural nucleoside analogue, cordycepin, that has the ability to significantly improve lysosomal function, enhance the activity of the lysosomal representative protease cathepsin B (CTSB), and promote the expression of the functional protein lysosomal-associated membrane protein 2 (LAMP2) on the lysosomal membrane. Cordycepin then restores the damaged autophagy level of aging cells by activating the classic AMPK and mTOR-p70S6K signaling pathways, thus inhibiting cell senescence in an H2 O2 -induced stress-induced premature senescence (SIPS) cell model. This study provides new theoretical support for the further development of cordycepin and clinical antiaging drugs to inhibit cell senescence and suggests that the regulatory mechanisms of lysosomes in senescent cells should be considered when treating age-related diseases.