Hypothesis

Combining intermittent dasatinib+quercetin (D+Q) with a low‑dose AMPK activator (e.g., metformin) creates a metabolic window that enhances natural killer (NK) cell–mediated senescent cell clearance, thereby prolonging the pharmacodynamic effect of senolytics and preventing the observed rebound in senescence biomarkers.

Mechanistic rationale

1. AMPK activation boosts NK cytotoxicity – Metformin increases AMPK activity in NK cells, upregulating perforin, granzyme B, and the expression of D1‑like dopamine receptors that sensitize NK cells to senescent‑cell‑associated signals【https://doi.org/10.1038/s41419-022-04562-w】.
2. Metabolic priming reduces SASP – AMPK signaling suppresses mTORC1, lowering NF‑κB‑driven SASP production in residual senescent cells, making them less immunosuppressive and more visible to immune surveillance【https://pmc.ncbi.nlm.nih.gov/articles/PMC12456441】.
3. Synergistic senolytic window – D+Q induces apoptosis of a bulk of senescent cells; the ensuing transient increase in intracellular AMPK (due to cellular stress) synergizes with exogenous metformin, creating a period where NK cells are both more active and senescent cells are less able to evade clearance.

Testable predictions

• In a randomized, double‑blind, placebo‑controlled trial of older adults with high baseline T‑cell p16^INK4A (top tertile), three arms will be compared: (i) D+Q alone (standard intermittent schedule), (ii) D+Q + low‑dose metformin given daily during the 2‑day senolytic window and continued for 2 weeks post‑dose, (iii) metformin alone.
• Primary outcome: change in plasma P1NP at week 4 and week 20. We predict that arm (ii) will show a significantly higher and sustained P1NP increase at week 20 compared with arm (i), indicating delayed re‑accumulation of senescent cells.
• Secondary outcomes: NK cell activation markers (CD107a, IFN‑γ) in peripheral blood, SASP cytokine panel (IL‑6, IL‑8, MCP‑1), and T‑cell p16^INK4A levels.
• Exploratory: PET‑based senescence imaging (if available) to assess tissue‑specific burden.

Falsifiability

If arm (ii) fails to show a statistically significant prolongation of the P1NP response or shows no improvement in NK activation markers relative to arm (i), the hypothesis that AMPK activation augments NK‑mediated senescent cell clearance to extend senolytic efficacy would be refuted.

Implications

A positive result would support a metabolically informed, intermittent senolytic regimen that leverages endogenous immune surveillance, addressing the durability challenge highlighted by transient biomarker responses and opening a path toward combinatorial senotherapy.