Role of Porphyromonas gingivalis-derived fibroblast-activating factor in bone resorption.

A 24-kDa protein was isolated from the outer membrane vesicles of Porphyromaonas gingivalis W50. This protein, referred to as fibroblast-activating factor (FAF), was examined for its bone-resorptive ability by the rat long-bone assay and the mouse bone marrow cell culture system. FAF resulted in a significant release of 45Ca from cultured bones, as well as the formation of tartrate-resistant acid phosphatase-positive monocytes. These cultures were compared with control cells. FAF therefore might be considered a significant bacterially expressed protein which could affect and modulate the resorption or destruction of tissue and alveolar bone in the local periodontal environment.