Study design: A review of the current literature on the role of matrix metalloproteinases in intervertebral disc degeneration.
Objective: To detail the characteristics of matrix metalloproteinases (classification, structure, substrate specificity and regulation) and to report previous studies of intervertebral discs.
Summary of background data: Degeneration of the intervertebral disc, a probable prerequisite to disc herniation, is a complex phenomenon, and its physiopathologic course remains unclear. Matrix metalloproteinases probably play an important role but have received sparse attention in the literature.
Methods: A systematic review of studies reporting a role of matrix metalloproteinases in intervertebral disc degeneration.
Results: In several studies, investigators have reported the presence of proteolytic enzymes from disc culture systems and disc tissue extracts in degenerated human intervertebral discs, especially collagenase-1 (MMP-1) and stromelysin-1 (MMP-3). The matrix metalloproteinases are regulated by specific inhibitors (tissue inhibitors of metalloproteinases, or TIMPS), cytokines (interleukin-1), and growth factors.
Conclusions: This field of application is of particular interest because conventional treatments are disappointing in chronic low back pain. Clinical trials with specific inhibitors of metalloproteinases are beginning in osteoarthritis.