Matrix metalloproteinase-3 production by human degenerated intervertebral disc

To assess its possible role in the pathophysiology of intervertebral disc degeneration, we investigated the production of matrix metalloproteinases-3 (MMP-3) using human intervertebral disc explant culture. Five normal and 10 degenerated disc specimens were used. The levels of MMP-3 released in the medium were measured with use of an enzyme immunoassay. The results showed that the level of MMP-3 in the degenerated group (0.57 mu g/ml/mg wet weight; n = 10) was significantly higher than that of the control group (0.29 mu g/ml/mg wet weight; n = 5) (p < 0.05). Immunostaining of MMP-3 revealed that the ratio of positive staining cells in the degenerated group was greater than that of the control group. These observations suggest that MMP-3 produced by human intervertebral disc may be involved in the intervertebral disc degeneration, particularly in the initiation of matrix degradation of intervertebral disc.