Abstract 43

Human Chondrocytes Express Protease-Activated Receptors: Possible Involvement of Thrombin-induced Cell Proliferation and Migration.

Renzhi Han, Lyn Kirilak, Craig Willers, Ming-Hao Zheng

School of Surgery and Pathology (Orthopaedics)
University of Western Australia

Fibrin sealant, with thrombin as its active component, has recently been recommended for use as tissue glue in autologous chondrocyte implantation (ACI). However, the effect of thrombin on chondrocyte proliferation, and the expression of associated protease-activated receptors (PARs) in human chondrocytes remains unclear. In this study, we sought to investigate the expression of PARs 1-4 within cultured autologous chondrocytes, the effect of thrombin on intracellular calcium and cellular proliferation, and the migration of human chondrocytes in coculture with fibrin sealant. Immunocytochemistry and RT-PCR was used to assess PARs expression in chondrocytes, thrombin and PAR agonist calcium response was assessed by fluorescence, the effect of thrombin was measured by the alamarblue assay, and chondrocyte migration was evaluated in co-culture with collagen membrane and fibrin sealant. We demonstrated that PARs 1-4 are indeed expressed by cultured human chondrocytes. Thrombin and PAR-1 agonist peptide both induced a fast intracellular Ca²⁺ elevation in human chondrocytes. In addition, thrombin, in concentrations ranging from 0.1 U/ml to 1 U/ml, was shown to significantly promote proliferation of cultured human chondrocytes after 48 hours, with maximum efficacy at 1.0 U/ml thrombin. Migration of human chondrocytes into fibrin sealant after co-culture with collagen membrane and fibrin sealant was observed after 48 hours. Taken together, these data suggest thrombin promotes proliferation and migration of human chondrocytes, at least in part through PAR-1 mediated cell signalling. Collectively, this data advocates the use of fibrin sealant as a component of the ACI technique.

Return to Listing of 2004 Abstracts
View Listing of 2005 Abstracts