Mechanotransduction of mandibular condylar chondrocytes under pressure

Abstract

To investigate the possible involved signal molecules in the mechanotransduction of mandibular condylar chondrocytes (MCCs) under pressure, in vitro cultured rabbit MCCs were incubated and pressed under continuous pressure of 90 KPa for 1 h and 6 h by hydraulic pressure controlled cellular strain unit. The signal molecules of integrin pathway and G protein pathway were detected step by step. The results showed that expression of all the signal molecules investigated here, including integrinα5β 1, F-actin, G protein, intracellular calcium, PKC, ERK1, JNK1, IL-4 and IL-6 increased under the pressure. At the same time, series of membrane or cytoplastic proteins, such as F-actin, PKC and ERK 1 and JNK1 showed characteristic translocation from cytoplasm to the membrane, to the nuclei, or to the perinuclear region, and underwent reversible binding interactions. There were only integrinβ 1, JNK1 and IL-4 in the long-term pressure group showed all the more higher than that of short-term pressure group. It was suggested that integrinα5β1, F-actin, G protein, intracellular calcium, PKC, ERK1, JNK1, IL-4 and IL-6 all participated in the mechanotransduction of mandibular condylar cartilage under continuous pressure. Mechanotransduction under long-term and short-term pressure may involve different dominant signal molecules. © 2008 Springer-Verlag.