SASP Reveals Metabolic Reprogramming on Both Sides

SASP has traditionally been studied mainly through inflammatory cytokines such as IL-6, but recent studies show that metabolic changes occur in both SASP-producing and responding cells. The first paper showed that upregulation of the mitochondrial pyruvate–citrate–acetyl-CoA axis increases acetyl-CoA availability, supporting histone acetylation and robust SASP gene expression. The second paper showed that SASP increases mitochondrial respiration in non-senescent cancer cells, while SASP-derived fructose drives complex I-dependent metabolic reprogramming that reduces plasma membrane cholesterol and weakens cell adhesion. Together, these studies show that metabolism contributes not only to SASP expression but also to the responses of surrounding cells, highlighting the importance of viewing SASP-mediated intercellular communication from a metabolic perspective.

Mitochondrial metabolism and epigenetic crosstalk drive SASP
(Martini et al., Nature, 2026)

Summary: 
In this study, the mitochondrial pyruvate–citrate–acetyl-CoA axis was shown to be upregulated in senescent cells and to support SASP expression through acetyl-CoA-dependent histone acetylation. Inhibiting pyruvate import or citrate export reduced SASP expression, while mitochondrial clearance decreased histone acetylation and SASP gene expression. Acetate supplementation partially restored histone acetylation and a subset of SASP genes, supporting acetyl-CoA as the metabolic link between mitochondria and SASP regulation.

Highlighted technique: 
To determine whether reduced SASP expression reflected generalized mitochondrial dysfunction, senescent fibroblasts with inhibited citrate transport were evaluated for OCR, ATP production by Seahorse analysis, mitochondrial superoxide by fluorescent probe, and mitochondrial morphology by TOMM20 imaging.

Combining senescence markers such as SA-β-gal, p16/p21 and SASP with OCR and mitochondrial ROS measurements can help distinguish generalized mitochondrial dysfunction from pathway-specific metabolic reprogramming underlying SASP changes. 

The chemotherapy-induced senescence-associated secretome promotes cell detachment and metastatic dissemination through metabolic reprogramming
(Cole et al., Nature Aging, 2026)

Summary: 
In this study, the mechanism by which SASP from chemotherapy-induced senescent cancer cells weakens adhesion of neighboring non-senescent cancer cells was investigated. SASP exposure increased mitochondrial respiration in bystander cells, while fructose enriched in the SASP drove complex I-dependent metabolic reprogramming and reduced plasma membrane cholesterol, resulting in weaker cell adhesion and increased detachment.

Highlighted technique: 
To distinguish senescence in SASP-producing cells from metabolic responses in recipient cancer cells, senescence was induced using the chemotherapy drug cisplatin and confirmed by SA-β-gal and proliferation markers. Recipient-cell metabolism was then assessed by Seahorse OCR and NAD⁺/NADH measurements.

Confirming senescence in SASP-producing cells with SA-β-gal while measuring OCR in bystander cells enables direct evaluation of SASP-induced metabolic responses. NAD⁺/NADH can provide a complementary readout when investigating complex I-associated redox changes.