Whether this functional derangement of the cell response is purely disease-dependent or reflects, at least in part, the normal aging of the cells is unclear at the moment. Recently, catabolic stress was shown to have the potential to induce chondrocyte senescence by overexpression of caveolin-1,39 a protein known to potentially induce senescence in other cells. For this and other reasons, age-related changes in chondrocyte behavior as one major cause of the development of OA is an appealing concept.2 In addition to age-related cellular changes, the ECM structure and composition of normal cartilage changes over time. For example, in older tissue there is an accumulation of dvanced glycation end-products (AGEs) within the cartilage matrix.40 These molecules can induce matrix degradation through the receptor for advanced glycation end-products (RAGE), a protein that is expressed by articular chondrocytes.41,42 In chondrocytes, stimulation of RAGE signaling leads to mitogenactivated protein kinase activation and increased nuclear factor κB activity, which mediate the induction of MMP-13,42 a known major matrix-degrading protease in osteoarthritic cartilage.43,44 Given the increased expression of RAGE in this tissue, RAGE signaling may have an important role in OA.42 Although aging as a major risk factor for OA is an interesting concept, our molecular understanding of the mechanisms behind this is insufficient at the moment.