The role of protease-activated receptor-1 in bone healing

Abstract

Protease-activated receptor (PAR)-1, a G-protein-coupled receptor activated by thrombin, mediates thrombin-induced proliferation of osteoblasts. The current study was undertaken to define the role of PAR-1 in bone repair. Holes were drilled transversely through the diaphysis of both tibiae of PAR-1-null and wild-type mice. Three days later, fewer cells had invaded the drill site from adjacent bone marrow in PAR-1-null mice than in wild-type mice, and a lower percentage of cells were labeled with [3H]thymidine in PAR-1-null drill sites. More osteoclasts were also observed in the drill site of PAR-1-null mice than in wild-type mice 7 days after drilling. New mineralized bone area was less in t..