Expression and Activity of Hyaluronidase in Human Periodontal Ligament Fibroblasts

Background: Hyaluronan is a major component of the extracellular matrix of periodontal ligament (PDL) contributing to the structural and functional integrity. Hyaluronans contribute to the buffering effect of the PDL during chewing, and they are also important in inflammation and wound healing. Hyaluronan is known to be synthesized and turned over by the resident PDL cells, although the mechanisms of hyaluronan metabolism still remain unclear. Hyaluronidase (HAase), an endoglycosidase, degrades hyaluronan into small fragments. Currently, 3 human HAases, HYAL1, HYAL2, and PH-20, have been identified and well characterized. Methods: This study was conducted to investigate the expression and activity of these HAases in cultured human PDL fibroblasts and to elucidate the mechanisms involved in hyaluronan metabolism under normal and inflammatory conditions. Human PDL fibroblasts derived from the periodontium of 3 premolars were cultured with or without interleukin (IL)-1β (0.1 to 10 ng/ml) and tumor necrosis f...