Abstract
Hepatocyte growth factor (HGF), also known as scatter factor (SF), is a motogen, mitogen and morphogen produced by mesenchymal cells that mainly acts on epithelial cells and is involved in osteoclast stimulation. This study examined the possible enhanced production of HGF/SF by human gingival fibroblasts upon stimulation with killed cells of Porphyromonas gingivalis strain 381 and its representative bioactive cellular components, fimbriae and lipopolysaccharide (LPS). P. gingivalis whole cells enhanced the production of HGF/SF detected by ELISA in culture supernates of the fibroblasts. Fimbriae prepared from P. gingivalis exhibited powerful HGF/SF-inducing activity in a concentration-dependent manner, with peak activity observed at 100200 µg/ml. The fimbriae-induced HGF/SF mRNA expression by the cells was also detected by reverse transcription-PCR. P. gingivalis LPS exhibited weak HGF/SF-inducing activity. The study also examined the HGF/SF-inducing activity of seven synthetic peptides corresponding to the segments of P. gingivalis fimbrial subunit protein. The peptides of residues 282301 and 302321, which exhibited antagonistic effects against P. gingivalis fimbriae-binding to human gingival fibroblasts in a previous study, showed weak activity, whereas other non-antagonistic peptides showed no significant activity. These findings indicated that P. gingivalis fimbriae enhanced production of HGF/SF by human gingival fibroblasts, whereas synthetic peptide segments of fimbrial subunit protein were not sufficient to exert the activity.