Effect of PTX and COX inhibitors in the aggrecan suppression by S1P. A) PTX partly abrogate the suppressing effect of S1P. The result of an assay on an OA sample is shown. B) Real-time PCR: aggrecan mRNA. OA chondrocytes were stimulated in vitro with S1P (10 μM) for 24 h and the mRNA was analyzed for aggrecan expression (N = 3). mel: meloxicam (1 μM), ind: indomethacin (25 μM).