Hypothesis

Estrogen signaling shifts the PI3K/AKT pathway isoform preference in female cells, converting senolytic Dasatinib+Quercetin (D+Q) from a pro‑clearance signal into a pro‑inflammatory trigger via preferential activation of AKT1 over AKT2, leading to NF‑κB‑mediated cytokine release.

Mechanistic Rationale

• Dasatinib inhibits Src/Bcr‑Abl and also dampens PI3K/AKT signaling; quercetin modulates PI3K activity through its flavonoid structure.[1]
• In male cells, basal AKT2 dominance supports metabolic survival; acute PI3K/AKT inhibition reduces SASP and promotes senescent cell apoptosis.[2]
• Female cells exhibit higher estrogen receptor‑α (ERα) expression, which upon ligand binding recruits p85 subunit of PI3K to the membrane, biasing signaling toward AKT1.[3]
• AKT1 activation stimulates mTORC1 and IKKβ, amplifying NF‑κB transcription of IL‑6, IL‑1β, and TNF‑α, offsetting senolytic clearance and raising inflammatory markers.
• This isoform switch explains the observed sex‑specific rise in CRP and IL‑6 after quercetin monotherapy in women.[2]

Testable Predictions

1. In isolated human senescent fibroblasts, D+Q will reduce SA‑β‑gal positivity in male‑derived cells but increase IL‑6 secretion in female‑derived cells unless AKT1 is pharmacologically inhibited.
2. Co‑treatment with an AKT1‑selective inhibitor (e.g., MK‑2206 at low dose) will abolish the quercetin‑induced inflammatory surge in female cells without affecting senolytic efficacy in males.
3. Estradiol supplementation to male senescent cultures will recapitulate the female inflammatory response to D+Q, an effect blocked by ERα antagonist fulvestrant.
4. In vivo, ovariectomized female mice treated with D+Q will show lower plasma IL‑6 compared with intact females, while estradiol replacement restores the increase.

Experimental Design

• Obtain primary dermal fibroblasts from male and female donors (age 60‑80), induce senescence via irradiation.
• Treat groups: vehicle, D+Q, D+Q+AKT1i, D+Q+ERα antagonist, estradiol pretreatment.
• Measure SA‑β‑gal, Annexin V/7‑AAD, secreted cytokines (IL‑6, IL‑1β, TNF‑α) by ELISA, and phospho‑AKT1/AKT2 levels by Western blot.
• Parallel ovariectomized mouse study with serum cytokine profiling and cardiac tissue senescence markers post‑aortic bypass mimic.

Potential Implications

If validated, the hypothesis would mandate sex‑stratified dosing, suggest AKT1 modulation as a rescue strategy for female patients, and reveal a hormonal gatekeeper of senolytic safety—guiding personalized senolytic regimens that avoid unintended inflammation.

Citations

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC12456441/ [2] https://www.nad.com/news/a-natural-senolytic-supplement-curbs-heart-aging-in-new-clinical-trial [3] https://aging-us.org/2025/04/senolytic-compounds-show-promise-in-targeted-alzheimers-treatments/