The Roles of Matrix Metalloproteinase-1, -2 in the Degenerative Spinal Diseases

Abstract

Objective: A number of evidence have suggested a pivotal role of matrix metalloproteinases(MMP) on the degeneration of intervertebral disc. Proteins of intervertebral disc mainly consist of collagen and proteoglycan. These proteins can be destructed by MMP, resulting in changes of main collagen type and degeneration of matrix proteins. The present study was to determine the different effects of MMP-1 and MMP-2 on the degenerative spinal diseases, resulting from aging process. Clinical Materials & Methods: Thirty-one patients were randomly selected among 350 patients whose discs were resected during operation from March 1997 to February 1999. Patients were divided into two groups: group I with spinal stenosis and group II with herniated intervertebral disc. Group II was subdivided into the ruptured(Group IIa) and unruptured(Group IIb). Increases in MMP-1 immunopositive cells were observed in both groups, as evidenced by immunocytochemical staining. However, in marked contrast, the number of MMP-2 immunopositive cells were only seen in group II. There was no significant difference between Group IIa and Group IIb. The MMP-2 immunopositive cells were increased in the anulus fibrosus of ruptured(Group IIa) more than unruptured(Group IIb), but statistically it was not significant. In addition, the immunopositivity of MMP-1 and MMP-2 was proportional to patients's age. Conclusion: These results strongly suggests the possible involvement of MMP-2, but not MMP-1 in progressive herniated intervertevral disc.