Substance P regulates the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinase in cultured human gingival fibroblasts

Background and Objective: Substance P may play a role in the pathogenesis of periodontal disease; however, its mechanisms of modulation are not clear. This study evaluated the effect of two concentrations of Substance P on the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cultured human gingival fibroblasts. Material and Methods: Fibroblasts were stimulated for 48 h with 10^?4 or 10^?9 m Substance P; untreated fibroblasts served as controls. The expression of MMP‐1, ‐2, ‐3, ‐7 and ‐11 and of TIMP‐1 and ‐2 was evaluated using real‐time polymerase chain reaction and western blotting. Results: There was a significant, concentration‐dependent stimulatory effect of Substance P on MMP‐1, ‐2, ‐3 and ‐7 and TIMP‐2 gene expression (p < 0.05), and a probable effect on MMP‐11 (p = 0.06). At the higher concentration (10^?4 m Substance P), MMP‐1, ‐2, ‐3, ‐7 and ‐11 and TIMP‐2 showed the greatest up‐regulation; at the lower concentration (10^?9 m Substance P), MMP‐1, ‐3 and ‐7 and TIMP‐2 exhibited diminished up‐regulation, with MMP‐2 and ‐11 showing down‐regulation (p < 0.05). Expression of TIMP‐1 was not affected by Substance P (p > 0.05). Western blotting confirmed that Substance P up‐regulated MMP‐1, ‐2, ‐3 and ‐11 and TIMP‐2. MMP‐1, ‐3 and ‐11 and TIMP‐2 showed greater up‐regulation at the higher Substance P concentration and diminished up‐regulation at the lower concentration. MMP‐2 was up‐regulated to a similar degree at both Substance P concentrations. Conclusion: In gingival fibroblast cells, Substance P at the higher concentration (10^?4 m ) induced greater up‐regulation of MMP‐1, ‐3 and ‐11 and TIMP‐2 expression, but at the lower concentration (10^?9 m ) induced diminished up‐regulation, which may represent a mechanism for modulating periodontal breakdown.