Osteoarthritis has long been framed as a mechanical wear-and-tear problem, but a growing body of evidence reframes it as a fundamentally inflammatory disease driven by biological aging — a distinction with major implications for how tens of millions of adults manage joint health as they age.
This review, published in Frontiers in Immunology, maps the molecular chain linking cellular senescence to cartilage destruction in osteoarthritis. As chondrocytes and synovial macrophages accumulate with age, they acquire the senescence-associated secretory phenotype (SASP), releasing pro-inflammatory cytokines, chemokines, and matrix-degrading proteases into the joint microenvironment. The review identifies five converging signaling cascades — NF-κB, MAPK/p38, mTOR, AMPK, and JAK/STAT — as the central amplifiers of this process, collectively driving extracellular matrix breakdown and sustained synovial inflammation. On the therapeutic side, the authors assess pharmacological agents already in clinical use or trials: the IL-1 receptor antagonist anakinra, the mTOR inhibitor rapamycin, and metformin, which modulates AMPK signaling. Emerging gene-based strategies — including microRNA modulation and CRISPR/Cas9 editing of SASP-regulating loci — are presented as longer-horizon options.
The framing of osteoarthritis as an "inflammaging" disease is not new, but this synthesis is useful for consolidating the mechanistic architecture underlying it. The five-pathway model underscores why single-target approaches have repeatedly disappointed in OA clinical trials: the disease is orchestrated by redundant, cross-talking networks rather than a single bottleneck. Metformin and rapamycin are particularly interesting candidates here, given their established human safety profiles and existing longevity-adjacent research. That said, this is a narrative review, not a meta-analysis or trial report — it synthesizes existing literature without generating new effect-size data. The CRISPR and microRNA strategies remain pre-clinical. Adults managing OA should note that the mechanistic case for targeting inflammaging is strengthening considerably, though translating these targets into approved joint therapies remains an active and unfinished project.
