Interleukin-25 regulates matrix metalloproteinase-2 and -9 expression in periodontal fibroblast cells through ERK and P38MAPK pathways.

Interleukin-25 (IL-25) has been recognized as a new member of the IL-17 family and implicated in various inflammatory pathology. We aimed to investigate the effects of IL-25 on the expression of matrix metalloproteinase-2 (MMP-2), MMP-8, and MMP-9 in periodontal fibroblast cells (PFCs), cell migration, cytoskeleton F-actin, and to explore the involved extracellular-regulated protein kinases (ERKs), P38 mitogen-activated protein kinase (P38MAPK) signaling pathways, and IL-17 receptor. To evaluate the expression of MMP-2, MMP-8, MMP-9, and F-actin, PFCs were treated by various doses of IL-25 (0, 20, 50, 100, and 500 ng/ml). Protein expression of extracellular metalloproteinase inducer (EMMPRIN) was also evaluated by western blot. Cell scratches experiment was performed to test the cell migration ability. ERK, P38MAPK, and Jun N-terminal kinase signal pathways and related expression of P-ERK and P-P38MAPK were examined after treatment of different doses of IL-25 and after treatment of inhibitors of ERK and P38MAPK. Immunofluorescence of MMP-2, MMP-9, and F-actin were evaluated after inhibitor treatment. IL-17RB small interfering RNA was used to examine the receptor of IL-25. IL-25 increased the protein expression of MMP-2 and MMP-9. MMP-8 and EMMPRIN expressions were not regulated by IL-25 in PFCs. Positive IF staining extended strongly from the central part to the whole cell. IL-25 mediated MMP-2, MMP-9, F-actin expressions and cell migration were regulated by P38MAPK and ERK pathways, and IL-17RB. SB203580 and U0126 blocked the effects of IL-25 through the inhibition of ERK, P38MAPK, P-ERK, and P-P38MAPK. The data indicate that IL-25 could regulate cell migration, MMP-2, and MMP-9 expression, but not MMP-8 expression, in PFCs. Moreover, the regulation effects were involved in ERK and P38MAPK pathways, and receptor IL-17RB.