Gene expression of MMP3, MMP13, ADAMTS5, LAMA4, and syndecan-4 in primary human chondrocytes of grade 0-I human osteoarthritic specimens in vitro when exposed to IL-1 (10 ng/mL) and to 2A3 antibody (monoclonal antibody blocking LAMA4). RT-PCR was performed after 3 h of treatment. MMP3 expression increased after exposure to IL-1 (*p < 0.03) and this was significantly inhibited by 2A3 (**p < 0.02). MMP13 expression was significantly elevated after IL-1 treatment (▲p < 0.03) as well as IL-1 and 2A3 treatment (■p < 0.04). Syndecan-4 expression was enhanced by IL-1, but not affected by blocking LAMA4. The results are presented as mean ± standard deviation (SD). Real-time RT-PCR results are expressed as mean ± SD percentage over control. Comparison between two groups was performed using Student’s t test. Differences between two groups were considered significant at the p < 0.05 level.