Hypothesis\n\nChronic use of non‑steroidal anti‑inflammatory drugs (NSAIDs) suppresses the early prostaglandin‑dependent signals that recruit and activate macrophages for senescent cell clearance, leading to accumulation of SASP‑secreting cells and accelerated aging.\n\n## Mechanistic Rationale\n\n- NSAIDs inhibit cyclooxygenase‑1/2 (COX‑1/2), reducing synthesis of prostaglandin E2 (PGE2) and prostacyclin (PGI2). These lipids act as chemoattractants for monocytes/macrophages and promote their phagocytic phenotype via EP2/EP4 receptors (see PGE2 macrophage recruitment).\n- Acute SASP releases CCL2 and other chemokines that depend on a prostaglandin‑rich microenvironment to efficiently draw monocytes to senescent foci (see early SASP immune recruitment).\n- When COX‑2 is blocked, monocyte infiltration is blunted, macrophage activation shifts toward an anti‑inflammatory M2 phenotype lacking the oxidative burst needed for senescent cell apoptosis (see macrophage phenotype in clearance).\n- Consequently, senescent cells persist, continue secreting IL‑6, IL‑8, IL‑1β, TNF‑α via NF‑κB/cGAS‑STING, driving low‑grade inflammaging and tissue dysfunction.\n\n## Testable Predictions\n\n1. In aged mice, long‑term ibuprofen treatment will increase senescent cell burden (p16^Ink4a^+ or SA‑β‑gal^+) in liver, kidney, and joint tissues compared with vehicle controls, despite lower serum IL‑6 levels.\n2. Administering a PGE2 analog (e.g., 16,16‑dimethyl‑PGE2) alongside ibuprofen will rescue macrophage infiltration and reduce senescent cell accumulation, confirming the prostaglandin dependence.\n3. In human observational cohorts, chronic NSAID users (>6 months, ≥3 times/week) will show higher epigenetic age acceleration (e.g., GrimAge residual) and elevated circulating SASP factors after adjusting for pain severity and comorbidities.\n4. Ex vivo, macrophages cultured with sera from NSAID‑treated patients will exhibit reduced phagocytosis of senescent fibroblasts labeled with p16‑GFP, an effect reversed by adding exogenous PGE2.\n\n## Potential Confounders and Controls\n\n- Control for underlying inflammatory disease severity by stratifying cohorts by diagnosis (osteoarthritis vs rheumatoid arthritis).\n- Use COX‑2‑selective inhibitors (celecoxib) vs non‑selective (ibuprofen) to dissect isoform contributions.\n- Monitor gastric mucosal integrity to ensure systemic drug exposure is comparable.\n\n## Implications\n\nIf validated, this hypothesis reframes NSAIDs not merely as symptom suppressors but as agents that may inadvertently inhibit a protective senescent‑cell surveillance system, suggesting that intermittent dosing, prostaglandin supplementation, or senolytic co‑therapy could mitigate hidden longevity costs.\n\n## References\n[1] PGE2 macrophage recruitment: https://pmc.ncbi.nlm.nih.gov/articles/PMC8976373/\n[2] Early SASP immune recruitment: https://pmc.ncbi.nlm.nih.gov/articles/PMC12937819/\n[3] Macrophage phenotype in clearance: https://doi.org/10.1038/nm.4324