Stimulation of epithelial cell matrix metalloproteinase (MMP‐2, ‐9, ‐13) and interleukin‐8 secretion by fusobacteria

Background/aims: Bacterial pathogens involved in periodontal diseases exert their destructive effects primarily by stimulating the host cells to increase their secretion of proinflammatory cytokines and matrix metalloproteinases (MMPs). This study aimed to determine the epithelial cell matrix metalloproteinase and interleukin‐8 (IL‐8) secretion upon exposure to fusobacteria. Methods: Eight different oral and non‐oral Fusobacterium strains were incubated with HaCaT epithelial cells. Gelatin zymography and Western blot analysis were performed to detect collagenase 3 (MMP‐13), gelatinase A (MMP‐2), gelatinase B (MMP‐9), and IL‐8 secretion by epithelial cells. Results: All Fusobacterium strains, especially Fusobacterium necrophorum ATCC 25286, Fusobacterium nucleatum ATCC 25586, and Fusobacterium varium ATCC 51644, increased MMP‐9 and MMP‐13 secretion. Fusobacterium simiae ATCC 33568, and to a lesser extent F. nucleatum and F. necrophorum, increased epithelial MMP‐2 secretion. F. nucleatum and F. necrophorum also increased IL‐8 secretion. F. varium ATCC 27725, a strain that only weakly stimulated MMP production, strongly increased the IL‐8 production, suggesting that their expression is differently regulated. Conclusion: We conclude that the pathogenic potential of fusobacteria may partly result from their ability to stimulate secretion of MMP‐9, MMP‐13, and IL‐8 from epithelial cells.