Proteinase-activated receptor-2 is required for normal osteoblast and osteoclast differentiation during skeletal growth and repair

Abstract

Proteinase-activated receptor-2 (PAR 2) is a G-protein coupled receptor expressed by osteoblasts and monocytes. PAR 2 is activated by a number of proteinases including coagulation factors and proteinases released by inflammatory cells. The aim of the current study was to investigate the role of PAR 2 in skeletal growth and repair using wild type (WT) and PAR 2 knockout (KO) mice. Micro computed tomography and histomorphometry were used to examine the structure of tibias isolated from uninjured mice at 50 and 90days of age, and from 98-day-old mice in a bone repair model in which a hole had been drilled through the tibias. Bone marrow was cultured and investigated for the presence of osteobla..