Abstract
OBJECTIVES: To determine the effects of histamine on matrix metalloproteinase (MMP) production by human articular chondrocytes (HAC) in vitro. METHODS: Conditioned culture medium from HAC cultures incubated with and without 20 microM histamine was assayed by enzymne linked immunosorbent assay (ELISA) for MMP-1, MMP-8, MMP-13 (collagenases 1, 2, and 3, respectively) and MMP-3 (stromelysin). Monolayer cultures of HAC were also immunostained for MMP-13 and MMP-3. RESULTS: The HAC cultures showed a significant increase in MMP-13 and MMP-3 production (2.2- and 1.9-fold, respectively) after treatment with 20 microM histamine for 24 hours, but MMP-1 and MMP-8 were unaffected. All cultures showed MMP-13 and MMP-3 detectable by immunolocalisation. MMP-3 was the more prominent enzyme as shown by both ELISA and immunolocalisation techniques. CONCLUSIONS: Histamine exposure increased both MMP-13 and MMP-3 production by HAC in vitro, thereby suggesting a pathophysiological role in the chondrocytic phenotype associated with degenerative changes in osteoarthritis.